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Biomedical subjects

J D Andrade

Publications and source records attributed to J D Andrade.

At least 55 records · Page 3Linked to original sources
PubMed1978

Pharmacokinetic model for salicyclate in cerebrospinal fluid, blood, organs, and tissues.

The developed pharmacokinetic model, an extension of the Bischoff--Dedrick model, simultaneously predicts the kinetic behavior of salicylate in cerebrospinal fluid, blood, organs, and tissues. The model, which is entirely different from conventional compartment models, is derived from basic considerations of drug distribution with biochemical and physiological meaning. The dog was studied at three different dosages of salicylate: therapeutic, moderate intoxication, and severe intoxication. The predicted kinetics of salicylate in cerebrospinal fluid, blood, plasma, liver, muscle, and adipose tissue by the model agreed well with the experimental data. The effectiveness of hemoperfusion treatment for the severely intoxicated dog by albumin-coated activated carbon and its effect on the kinetic behavior of salicylate in cerebrospinal fluid, blood, organs and tissues were studied. The model was also applied to predict the kinetic changes of salicylate in the body during and after the extracorporeal treatment. The predicted results also agreed with the experimental data.

Adipose Tissue↗
PubMed1978

Surface tension measurements on methacrylate monomer solutions, selected solvents, and gel extracts.

The surface tensions of selected methacrylate monomer and solvent solutions were measured, and calibration curves were generated. The curves were then used to deduce the amounts of water soluble extractables in methacrylate hydrogels by measuring the surface tension of the extractant. The detectability limit (parts per 10,000) and the overall sensitivity of the method suggests its possible use as an extraction monitor test for related biomaterials.

Acrylates↗
PubMed1976

Pharmacokinetic model for simultaneous determination of drug levels in organs and tissues.

An extension of the Bischoff-Dedrick pharmacokinetic model is presented. This model is derived from basic considerations of drug distrubition with physiological and anatomical meaning. The Bischoff-Dedrick model can simultaneously predict drug distribution with time in blood, organs, and tissues of pharmacological interest. The parameters are applied to a 15-kg standard dog. The experimental kinetic data of thiopental in brain, plasma, liver, lean tissue, and adipose tissue in a dog are used to demonstrate the feasibility of the model. Allowable variations in the parameters are determined. In general, the kinetics of drug distribution in blood, organs, and tissues depend on the drug dosage, lipid solubility, partition coefficients, metabolism rate, excretion rate, protein binding, route of administration, sizes of organs and tissues, and blood flow rates through organs and tissues. These factors enter the kinetic model separately and explicitly so their effects on the kinetics of drug distribution can be studied to provide valuable information for optimal therapy.

Animals↗
PubMed1976

Platelet retention by albuminated glass and polystyrene beads.

Ex vivo platelet retention by albuminated glass and polystyrene beads has been evaluated as a function of flow rate, bead surface area, blood exposure time and albumin treatment. The stability of the albumin coatings as well as scanning electron microscopy of the various surfaces before and after blood exposure has also been included. Results indicate that platelet retention is sensitive to changes in the above parameters and that albumin pretreatment of different substrates can decrease platelet retention. This decrease is substrate dependent in that platelet retention is different for the albuminated glass and polystyrene substrates. Chemical analysis of the substrate materials by X-ray photoelectron spectroscopy (XPS) as well as bulk chemical analysis is also reported.

Animals↗
PubMed1975

Activated carbons for medical applications. In vitro microparticle characterization and solute adsorption.

Activated carbon is a high surface area adsorbent. Its ability to adsorb nitrogenous metabolic wastes and exogenous poisons from blood has been well documented. Polymeric coatings on activated carbon enhance its biotolerability and make it feasible for use in hemoperfusion devices. The only drawback seems to be the presence of microparticles on the carbon surface. These particles may become emboli during hemoperfusion. This paper describes a series of in vitro tests used to evaluate many commercially available granular and pelletized activated carbons. The tests were as follows: 1) creatinine adsorption capacity and kinetics, 2) initial cleanliness, 3) washability, 4) attrition resistance, and 5) carbon particle surface morphologymone grade of activated carbon has been chosen for hemoperfusion studies on the basis of the above evaluations; The nature of the microparticles and the approach used to remove them from this carbon is described.

Adsorption↗
PubMed1973

Enzyme electrodes.

From the discussion of electrodes and enzymes herein, and from the accounts of enzyme electrodes that have appeared in the literature, clinical determinations of certain metabolites and soluble enzymes by means of enzyme electrodes seem quite feasible. Such devices may be made highly specific by the use of appropriate enzymes and a high degree of accuracy can be obtained. Instantaneous and continuous determinations can be made from physiological fluids, and undesirable physiologic responses can theoretically be minimized, thus making long-term clinical monitoring a possibility. Enzyme electrodes may also have a useful lifetime and meet other practical requirements.

Catalase↗