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Biomedical subjects

J A Owen

Publications and source records attributed to J A Owen.

At least 19 recordsLinked to original sources
PubMed1979

A comprehensive laboratory computer system working round the clock.

The special features of a laboratory computer system operated by laboratory staff around the clock are presented. The system provides registration of work, production of worksheets, on-line data acquisition and reporting results. The reasons for the special design features are discussed.

Allied Health Personnel↗
PubMed1979

Reaction of vaginal tissue of rabbits to inserted sponges made of various materials.

Sponges of the same size made of collagen (CS), polyurethane (PU), polyvinylalcohol (PVA) and acetylcellulose (AC) were inserted for 10 days in the vaginas of 22 rabbits. Light and scanning electron microscopy of the vaginal wall and its mucosal lining showed signs of cytotoxicity only with PU and AC while CS and PVA picture did not differ from sham controls. In order to explain the reasons for the toxic effects, all sponges were extracted into aqueous or organic solvent media and analyzed by gas liquid chromatography. Only several minute peaks in organic solvents were found. Extracts of all sponges tested for cytotoxicity in fibroblast cultures showed significant inhibition of H3-thymidine uptake. Nevertheless, extract of collagen sponge was significantly less cytotoxic than the extracts of all other sponges.

Animals↗
PubMed1979

Theophylline-7-acetic acid: lack of absorption and therapeutic effectiveness.

A double-blind cross-over trial was conducted to evaluate the effectiveness of oral theophylline-7-acetic acid (T7AA) in 13 asthmatic patients. Pulmonary function tests showed no difference between T7AA and placebo. No T7AA or theophylline was found in the sera of these patients or of healthy volunteers who took T7AA tablets or syrup.

Adult↗
PubMed1979

The importance of liver in normal and silicotic lung-lipid homeostasis: 3. Triacylglycerols.

Early lung silicosis in rats activates the liver for triacylglycerol (TG) biosynthesis. The newly formed liver TG seems mobilized to the silicotic lung, as indicated by increased lung TG content and specific activity. These TG changes are associated with decreased TG content and increased TG specific activity in the liver. Serum TGs are also decreased at the study times of 6, 24, 72, and 144 h post intrapulmonary silica treatment.

Acute Disease↗
PubMed1978

Reliable fifteen-minute assay for theophylline.

We describe a reliable, rapid high pressure liquid chromatography assay for serum theophylline which can be performed on 0.5 ml or smaller samples. The procedure involves extraction, centrifugation and sampling all in the same disposable centrifuge tube. In the therapeutic range the coefficients of variation for within-day and day-to-day assays are 1.0% and 2.6%, respectively. The sensitivity of the method is better than 1 microgram/ml in serum. The minimum number of steps, rapid elution and use of only peak heights contribute to the reliability and rapidity of the assay.

Chromatography, High Pressure Liquid↗
PubMed1978

Dealing with specimen problems in a computerised clinical chemistry laboratory.

The use of a laboratory computer system to deal with specimen problems is described. Problems such as 'insufficient material' or 'haemolysis' are entered by reception staff or by bench workers so that resolution of the problem will not be overlooked; problems are then listed and dealt with by the duty biochemist. Specimens on printed worksheets are annotated 'urgent' where appropriate. Results obtained on-line, which are above top standard, automatically cause the specimen to reappear on the next worksheet marked 'dilution required'. Data relating to its use over a three-month period are presented together with some comments on the causation of specimen problems and their prevention.

Chemistry, Clinical↗
PubMed1978

Spectrophotometry of theophylline-7-acetic acid and theophylline.

A spectrophotometric assay procedure is described for individually measuring theophylline-7-acetic acid and theophylline in 2.0 ml of serum. Absorbance is a linear function of concentration over a range of 0.5-40 mg/liter for theophylline-7-acetic acid and 0.5-40 mg/liter for theophylline. No endogenous or exogenous compounds were found that interfere with theophylline-7-acetic acid determinations. As with other spectrophotometric theophylline assays, theobromine and, to a slight extent, phenobarbital interfere with theophylline determinations.

Humans↗
PubMed1977

Effect of collagen crosslinking on the rate of resorption of implanted collagen tubing in rabbits.

Collagen tubes were tanned with glutaraldehyde for different periods of time. Some were oxidized with periodate and sterilized with either 60Co (1.5 Mrad) or propylene oxide. The tubes were coated with polyfilamentous polyester fabric, filled with x-ray contrast material, and implanted subcutaneously in rats and rabbits. Rate of resorption was ascertained by x-ray procedure of progressive leakage of contrast material. A close relation between tanning time of the collagen fabric-combined prostheses and rate of their resorption in subcutis was found in both rats and rabbits. In rabbits, however, the implants were resorbed at a significantly faster rate than in rats. No effect of oxidation of collagen on the resorption was observed. Collagen tubes tanned for shorter time periods and sterilized with propylene oxide were more resistant to degradation than those sterilized with irradiation. This difference was absent, however, with material tanned for longer times. The mechanism of resorption of implanted collagen tubes was studied by morphological methods. The role of inflammatory cells in resorption is documented. The paper indicates the advantages as well as limits of the x-ray method of studying the resorption rate of biodegradable materials.

Animals↗