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D D Schottelius

Publications and source records attributed to D D Schottelius.

7 recordsLinked to original sources
PubMed1992

Surface characterization of activated charcoal by X-ray photoelectron spectroscopy (XPS): correlation with phenobarbital adsorption data.

X-ray photoelectron spectroscopy (XPS) was used to identify the functional states of carbon existing on the surfaces of various activated charcoals. The relative percentages of carbon, oxygen, and detectable trace elements comprising the activated charcoal surfaces were determined. Analysis of the carbon core-electron binding energy region revealed the existence of one hydrocarbon state (C-H, C-C are indistinguishable) and three oxygen-containing functional states. These states were hydroxyls or ethers (C-O), carbonyls (C = O), and carboxylic acids or esters (O-C = O). The C-O functional state contributed approximately 60-70% to the total percentage of oxygen-containing states. A very good correlation existed between the apparent areas occupied on the adsorbent surface per phenobarbital molecule and the relative percentages of the C-O functional state. Previously reported heat of displacement results for phenobarbital adsorption are now explained since the C-O state appears to be the primary site involved in the binding of phenobarbital by the activated charcoals.

Adsorption↗
PubMed1979

Electroencephalographic absence status with minimal behavior change.

Difficulty in correlating EEG abnormalities with clinical seizures is emphasized in this case report of an epileptic patient with electrical status epilepticus and normal behavior. In addition, the usefulness of dichotic listening tests in the identification of subtle perceptive and expressive impairments is illustrated in this same patient at a time of noncompliance with anticonvulsant therapy.

Adult↗
PubMed1979

Decreased phenytoin levels in antineoplastic therapy.

A case history is reported illustrating the difficulties which may be encountered in maintaining seizure control in patients being treated with antineoplastic therapy. The maintenance of therapeutic serum levels of phenytoin during combined cis-platinum and bleomycin sulfate therapy suggests an absorptive defect, possibly related to damage of the intestinal mucosa. This defect did not appear to alter the absorption of primidone or phenobarbital, since increased dosages were not necessary to maintain these drugs within therapeutic ranges.

Adult↗
PubMed1976

Use of phenytoin serum levels in a case of status epilepticus.

Serum anticonvulsant determinations made possible the identification of an unusual cause of status epilepticus and assisted with appropriate therapy in an epileptic patient with second-degree burns. The seizures were associated with a serum phenytoin concentration of 3.5 mug per milliliter. This suboptimal concentration of drug developed despite continuation of the patient's customary oral dose of phenytoin led to the conclusion that the unexpected decrement in serum anticonvulsant concentration was related to an experiment in absorption of that drug, possibly caused by the concurrent administration of oral oxacillin.

Adult↗
PubMedDate not supplied

Phenytoin pharmacokinetics: before and after folic acid administration.

Phenytoin (PHT) exhibits linear and Michaelis-Menten pharmacokinetics. PHT decreases serum folate; the vitamin folic acid (FA) is hypothesized to be a cofactor in the metabolism of PHT. The depletion of serum folate may explain the unpredictability of measured total serum PHT concentrations and time to steady state as compared with the Michaelis-Menten predictive calculations. We examined PHT pharmacokinetics before and after FA supplementation in 13 healthy male volunteers. The study was divided into two phases. Phase I determined V(max) (mg/day) and Km (micrograms/ml) of PHT to calculate PHT doses needed for the second phase. Phase II was a four-way cross-over study to examine the effect of 1 and 5 mg FA on total serum PHT concentrations 1 microgram/ml less and 5 micrograms/ml greater than the subject's Km, Km - 1 and Km + 5, respectively. Predicted versus measured total serum PHT concentrations, t90% (days to steady state), and the effect of FA were calculated for Km - 1 and Km + 5 before and after 1 or 5 mg FA. The measured total serum PHT concentration was always greater than the calculated concentration (p less than 0.05), and t90% was always longer than the calculated t90% (p less than 0.05) for Km - 1 before FA (all subjects decreased serum FA); the same was observed for Km + 5. If folate is assumed to be a cofactor in PHT metabolism, these results are expected, because depletion of the vitamin would indicate less folate to drive the metabolism of PHT, resulting in higher total serum PHT concentrations and longer time to reach steady state.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗