Biomedical subjects

J A Eliason

Publications and source records attributed to J A Eliason.

10 recordsLinked to original sources

PubMed1990

Staining of the conjunctiva and conjunctival tear film.

Both the distribution of tear fluid over the conjunctiva and any injury to the conjunctival epithelium can be made visible by instilling a fluorescent solution into the eye and observing with an appropriate combination of excitation and barrier filters. Sulphorhodamine B, which has an orange fluorescence that can be separated from the green natural fluorescence of the ocular tissues, gives a greater contrast than fluorescein. The tear film is seen to cover the surface of the conjunctiva and to be concentrated in its folds. Small circular areas of thin tear film appear transiently in the neighbourhood of the limbus after a blink. Occasional cells stain on the normal conjunctiva, particularly in the interpalpebral area. The density of the staining increases in dry eye conditions. Conjunctival trauma is sensitively revealed by the method, and its healing can be followed. Hard contact lenses are seen to traumatize continually the inferior limbal conjunctiva in symptomless wearers.

Conjunctiva↗

PubMed1990

A comparison between interrupted and continuous suturing techniques in keratoplasty.

A comparison between continuous and interrupted techniques of suturing in penetrating keratoplasties was made using autologous grafts in rabbits. Wound strength was determined using both a tensiometer and blow-out pressure measurements. Histologic examination of the wounds was also carried out, and clinical observations were made of the behavior of vascular growth through the wound in prevascularized corneas to further characterize the suturing techniques and the healing process. We found no difference in blow-out pressures between the two groups, but a significant increase in healing in the interrupted suture group, as measured by the tensiometer, was observed. Other differences were noted in the clinical course and histology, including a greater ease of vessels traversing the wound and more inflammatory cells in the wound area with interrupted sutures.

Animals↗

PubMed1988

Topical prostaglandin E2 effects on normal human intraocular pressure.

This was a double-masked, randomized, paired comparison with vehicle trial of a topically administered prostaglandin (PG)E2 in healthy human volunteers. A statistically significant decrease of the intraocular pressure in these non-glaucomatous volunteers occurred at six hours following one drop of 0.02% solution that persisted to the last measurement of IOP at the 24 hour examination. Significant elevation in the intraocular pressure was present at one and two hours following the eye drop instillation. All volunteers reported transient ocular side effects related to drug administration, including mild eye ache and intermittent photophobia for a duration of 2 to 4 hours. These symptoms were associated with a transient conjunctival vasodilation, but with no evidence of anterior chamber cells and flare or ciliary flush as determined by slit lamp examination. The results of this study suggest that PGE2, or a derivative, may offer a new class of topically effective ocular hypotensive agents useful in lowering the intraocular pressure of glaucoma patients.

Administration, Topical↗

PubMed1987

Proliferation of vascular endothelial cells stimulated in vitro by corneal epithelium.

Angiogenic activity in the corneal epithelium has been reported in an in vivo system. This study was undertaken to determine if this property would also be manifest in a direct fashion in vitro. Experiments were performed using rabbit vascular endothelial cells in culture. Rabbit corneal epithelial homogenate, medium exposed to corneal epithelial cultures (epithelial conditioned medium) and corneal keratocyte homogenate were tested for their mitogenic potential. Both corneal epithelial homogenate and epithelial conditioned medium were found to significantly increase the proliferation of vascular endothelial cells. This effect was dose dependent, manifest in media containing different sera and heat stable. Keratocyte homogenate, when prepared in the same manner, was not mitogenic.

Animals↗

PubMed1986

Preoperative prediction of hyphemas.

In a prospective study, 139 patients undergoing cataract extraction were evaluated preoperatively with a panel of coagulation studies: prothrombin time, partial thromboplastin time, platelet count, and total bleeding time. Patients were monitored postoperatively for the presence of a hyphema which was then correlated with the test results. There was an overall incidence of 10.8% hyphemas in the population, and a statistically significant correlation was revealed with abnormal test results only if all the tests were considered together.

Bleeding Time↗

PubMed1985

Angiogenic activity of the corneal epithelium.

A homogenate of corneal epithelial cells was tested to determine if it could induce vascularization in the cornea. Both fresh and cultured cells were used as sources of the homogenate which was evaluated in vivo using a self-contained system to perfuse it constantly into the corneal stroma. A vigorous growth of vessels resulted when the concentration of the homogenate exceeded a threshold of 20 micrograms per ml total protein. This capacity was not destroyed when the homogenate was heated. As a preliminary refinement of this response white blood cells were eliminated from the model with whole body X-irradiation. Vascularization occurred in leukopenic animals but was less than that observed in normal animals. It is concluded that the epithelial homogenate is able to provoke corneal vascularization in the absence of leukocytes.

Angiogenesis Inducing Agents↗

PubMed1982

Corneal epithelial cell cultures on stromal carriers.

Exposure of denuded rabbit corneal stromal carriers for 24 hr at 37 degrees C to suspensions of rabbit corneal epithelial cells grown in tissue culture resulted in the establishment of a cell layer on the carriers. The cell layers persisted for at least 1 week of incubation and were one to three cells thick. They consisted of healthy-appearing cells with normal intracellular organelles and intercellular desmosomal connections. After 2 to 7 days of incubation the cells were still capable of DNA replication and produced hemidesmosomes and basement membrane. This system is useful for in vitro studies of substrate requirements for hemidesmosome and basement-membrane formation by corneal epithelial cells.

Animals↗

PubMed1980

An ocular perfusion system.

An enclosed system is described utilizing an osmotically driven pump to continuously deliver a solution to a variety of intraocular locations. The behavior of this system is illustrated by using it to measure the fluorescein turnover rate in the anterior chamber.

Animals↗

PubMed1980

Insect contamination of a cornea stored in M-K medium.

We report the unusual case of contamination with an insect of corneal donor tissue stored in M-K medium. Some possible explanations of this occurrence are proposed, and suggestions are made to help prevent its recurrence.

Animals↗

PubMed1978

Leukocytes and experimental corneal vascularization.

The growth of blood vessels toward corneal burns was compared in normal rabbits and those depleted of their white cells by exposure to X-irradiation. By the fourth day following injury, new vessels were present in all control and leukopenic animals. Histologic examination failed to demonstrate infiltrating cells in the leukopenic animals. In the absence of inflammatory cells, the cornea has the capacity to undergo vascularization in response to an injury. It is suggested that the epithelium is a source of a vasostimulating substance.

Animals↗