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Biomedical subjects

D L Wilson

Publications and source records attributed to D L Wilson.

At least 145 records · Page 8Linked to original sources
PubMed1976

Sensitive GLC procedure simultaneous determination of phenytoin and its major metabolite from plasma following single doses of phenytoin.

An improved GLC procedure was developed for the simultaneous determination of phenytoin and its metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin, in plasma and urine following enzyme hydrolysis. After extraction, the drug, the metabolite, and the internal standard, 5-(p-methylphenyl)-5-phenylhydantoin, are measured by GLC with flame-ionization detection as their respective methyl derivatives following flash-heater methylation with trimethylanilinium hydroxide. The drug and metabolite give well-resolved symmetrical peaks on a phenyl methyl silicone column, and the method has a sensitivity of 150 ng/ml of phenytoin and 125 ng/ml of the metabolite. GLC-mass spectral evidence is presented for the formation and intact determination of methyl derivatives of the drug, its metabolite, and the internal standard.

Administration, Oral↗
PubMed1976

Alteration of protein metabolism in individual, identified neurons from Aplysia.

A search for control mechanisms governing protein metabolism in neurons from Aplysia californica has uncovered two examples of altered patterns of newly synthesized proteins: (1) The pattern of newly synthesized proteins in the R2 neuron is altered when protein synthesis occurs at elevated temperatures (22-30 degrees C as compared with 13-15 degrees C). (2) The processing of newly synthesized 12,000 dalton (12k) material to 6-9,000 dalton (6-9k) size in the R15 neuron (Strumwasser, F. and Wilson, D.F. [1976], J. Gen. Physiol., in press) can be blocked by certain ion replacements. If acetate replaces chloride in the incubation medium during the synthesis of 12k material, an early step in the processing, prior to the actual breakdown of 12k material, is blocked. Experiments with RNA-synthesis inhibitors indicate that none of the mRNAs which code for abundantly synthesized protein species in the R2 or R15 neurons have short (less than 4 hr) half-lives. This result has implications for an earlier report of regulation of protein synthesis in the R15 neuron.

Acetates↗
PubMed1976

Patterns of proteins synthesized in the R15 neuron of Aplysia. Temporal studies and evidence for processing.

The time-course of changes in the pattern of newly synthesized proteins in the R15 neuron of the parietovisceral ganglion of Aplysia californica has been studied at 14 degrees C. 5% polyacrylamide gels containing sodium dodecyl sulfate (SDS) have been used to separate newly synthesized (leucine-labeled) proteins from the neuron. We have demonstrated that the pattern of newly synthesized proteins from the R15 neuron does not change significantly if 5-h pulses of labeled leucine are given during the first 72 h of in vitro incubation of the excised ganglion. However, the level of leucine incorporation begins to decline somewhere between 17 and 43 h after the ganglion is isolated; at 43 and 69 h the levels of incorporation fell to 29 and 10% of the initial level, respectively. A number of conclusions have been drawn from the use of a sequential, double-label type of experiment in the same cell. There is processing of SDS-soluble, 12,000-dalton (12k) material to 6,000-9,000-dalton (6-9k) material. These materials are the two major peaks on gels after long labeling periods and together account for about 35% of all newly synthesized proteins. After synthesis of 12k material, there is a gradual disappearance of 12k (half-life about 8 h) and simultaneous appearance of 6-9k material on the gels, as the postsynthesis "chase" period of ganglia incubation is increased. The processing of 12k to 6-9k material occurs even in the presence of anisomycin, a protein syntehsis inhibitor, during the chase period. While the rate of 12k to 6-9k conversion can vary from cell to cell, it appears to remain consistent within, and is characteristic of, any individual R15. We detect no circadian rhythm in either the rate of 12k synthesis or the rate of 12k to 6-9k processing with 5-h label periods. These results are discussed in relation to the roles of 12k and 6-9k material in the R15 neuron.

Animals↗
PubMed1975

A suture-reinforced scleral sling. Technique for suspension of the ptotic upper lid.

A frontalis sling procedure for ptosis repair, employing preserved human bank sclera and polyfilament, cable-type, ophthalmic (Supramid Extra) suture in combination has been devised and tried. Results indicate that these two readily available materials that are now used separately may be combined for lid suspension. They are easy to work with and produce lasting results.

Adult↗
PubMed1975

A new intraocular foreign body retriever.

A new intraocular foreign body retriever especially suited for removal of small nonmagnetic foreign bodies was devised. Initial clinical trials have proved satisfactory, especially with vitreous surgery.

Eye Foreign Bodies↗
PubMed1971

Molecular weight distribution of proteins synthesized in single, identified neurons of Aplysia.

Parietovisceral ganglia from Aplysia californica were incubated in medium containing leucine-(3)H. Single, identified nerve cell somas were isolated from the ganglia, and their proteins extracted and separated by electrophoresis on 5% SDS-polyacrylamide gels. The distribution of total or newly synthesized proteins from the single neurons was determined by staining or slicing and liquid scintillation counting of the gels. Experiments showed that: (a) a number of proteins were being synthesized in abundance in the nerve cells; (b) different, identified neurons showed reproducibly different labeling patterns in the gels; (c) cells R2 and R15, which showed different distributions of radioactivity in the gels, had similar staining patterns; and (d) there was significant incorporation into material of high (>75,000) molecular weight in most of the cells.

Action Potentials↗
PubMed1969

A template-selective inhibitor of in vitro transcription.

A macromolecular factor, TF1, has been isolated from bacteriophage SP01-infected B. subtilis. TF1 selectively inhibits in vitro transcription of SP01 and related viral DNA. Evidence is presented regarding these properties of the repressor-like TF1: (1) template and conformational specificity; (2) interaction with DNA rather than RNA polymerase; (3) trypsin sensitivity; (4) reversibility of action; and (5) ability to block initiation, but not propagation, of RNA synthesis.

Bacillus subtilis↗