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Biomedical subjects

M E Whitten

Publications and source records attributed to M E Whitten.

13 recordsLinked to original sources
PubMed1999

A novel form of rhodopsin kinase from chicken retina and pineal gland.

The G protein-coupled receptor kinases (GRKs) are important enzymes in the desensitization of activated G protein-coupled receptors (GPCR). Seven members of the GRK family have been identified to date. Among these enzymes, GRK1 is involved in phototransduction and is the most specialized kinase of the family. GRK1 phosphorylates photoactivated rhodopsin (Rho*), initiating steps in its deactivation. In this study, we found that chicken retina and pineal gland express a novel form of GRK that has sequence features characteristic of GRK1. However, unlike bovine GRK1 which is farnesylated, chicken GRK1 contains a consensus sequence for geranylgeranylation. Peptides corresponding to the C-terminal sequence of chicken GRK1 are geranylgeranylated by a cytosolic extract of chicken liver. Based on results of molecular cloning and immunolocalization, it appears that both rod and cone photoreceptors express this novel GRK1. These data indicate a larger sequence diversity of photoreceptor GRKs than anticipated previously.

Amino Acid Sequence↗
PubMed1993

Using the oculocephalic reflex to assess effective retrobulbar anesthesia.

In order to confirm effective retrobulbar anesthesia, we attempted to stimulate the oculocephalic reflex (the doll's head phenomenon) in 40 consecutive patients undergoing elective cataract extraction with intravenous sedation. Thirty-nine of these 40 patients had a positive response, exhibiting the reflex in the nonanesthetized eye but not in the anesthetized eye. Using this test in sedated patients obviates interrupting surgery to administer additional block under less than optimal, uncontrolled conditions.

Anesthesia, Local↗
PubMed1981

Argon laser trabecular surgery in uncontrolled phakic open angle glaucoma.

Thirty-five phakic eyes from a predominantly black population with clinically uncontrolled open angle glaucoma underwent argon laser treatment to 360 degrees of the trabecular meshwork. The intraocular pressure in the untreated eye was used as a control whenever possible. The mean pressure change in the treated eye at four months showed a decrease of 10.0 mm Hg (P less than 0.001). This effect was maintained throughout the 18-month follow-up period. Thirty-four of the 35 eyes (97%) were clinically controlled with pressures averaging less than 20 mm Hg. The procedure appears to function by improving outflow facility as manifested by a statistically significant increase in outflow for six months post-treatment. The major complication was the formation of peripheral anterior synechiae. These synechiae were localized and did not affect the success of the procedure. Argon laser trabecular surgery appears to be effective in lowering intraocular pressure with many advantages over standard filtering surgery.

Adult↗