Tritiated thymidine undergoes decomposition by self-radiolysis. As shown by beta liquid-scintillation measurement and by autoradiography, the resultant breakdown products did not label DNA, but entered macromolecules, other than nucleic acid, contained in the cytoplasm. Caution should be exercised in using aged tritiated thymidine solutions.

Autoradiography↗

PubMedDate not supplied

Thymoxamine hydrochloride: an alpha-adrenergic blocker.

Thymoxamine is an alpha-adrenergic blocking agent which works by competitive antagonism of norepinephrine. It is the only alpha-adrenergic blocker available which has tolerable side effects when used as an ophthalmic solution. When used as a 0.5% solution it consistently produces miosis without affecting the intraocular pressure or the ciliary muscle-controlled facility of outflow. The only regularly reported side-effects at this concentration are transient burning and conjunctival hyperemia. Potential applications of thymoxamine include reversal of phenylephrine mydriasis, treatment of angle-closure glaucoma, treatment of persistent mydriasis after penetrating keratoplasty for keratoconus, reversal of lid retraction in thyroid ophthalmopathy, testing to differentiate angle-closure glaucoma from open-angle glaucoma with narrow angles, aiding in repositioning and maintaining the position of intraocular lenses, treatment of pigmentary glaucoma. Thymoxamine may also contribute to a better understanding of the adrenergic nervous system on aqueous dynamics.

Adrenergic alpha-Antagonists↗

PubMedDate not supplied

Intracameral sodium hyaluronate before fistulization.

Explore the source record for details and available documents.

Anterior Chamber↗

PubMedDate not supplied

Plateau iris syndrome.

Eight cases of the plateau iris syndrome are presented. The "plateau iris syndrome" should be differentiated from the "plateau iris configuration." The "configuration" refers to a preoperative condition in which gonioscopically confirmed angle-closure glaucoma occurs, but the iris plane is flat and the anterior chamber is not shallow axially. In most cases, the angle-closure glaucoma associated with the plateau iris configuration is cured by a peripheral iridectomy. "Plateau iris syndrome" refers to a postoperative condition in which a patent iridectomy has removed the relative pupillary block which is ordinarily important in causing angle closure, but gonioscopically confirmed angle closure recurs without shallowing of the anterior chamber axially. Plateau iris syndrome is rare compared to the configuration, which itself is not common. In the syndrome, angle closure usually occurs in the early postoperative period but may occur long after iridectomy when the pupil dilates spontaneously or in response to mydriatic agents. It usually occurs in a younger age group than ordinary angle-closure glaucoma. The treatment is the use of pilocarpine postoperatively as long as it is needed. This syndrome must be considered in the differential diagnosis when the intraocular pressure rises unexpectedly following an adequate peripheral iridectomy procedure for angle-closure glaucoma.

Adult↗