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Biomedical subjects

A Fleck

Publications and source records attributed to A Fleck.

At least 55 records · Page 3Linked to original sources
PubMed1979

Successful operation of a regional scheme for the maintenance of automatic analysers.

The main operational and financial aspects of the maintenance service provided by the West of Scotland Health Boards' Department of Clinical Physics and Bio-Engineering (DCPB) to the clinical chemistry laboratories in the region are described. The scheme, in operation since March 1976, covers all breakdown servicing and engineering preventive maintenance for Technicon Auto-Analyzer equipment valued at pounds 1 1/4 million in terms of direct replacement costs. The engineering team works closely with the laboratory staffs to ensure that the performance of the equipment is maintained to specification. The direct economies for the Health Boards through savings in maintenance contract charges total around pounds 60,000 per year. In addition, considerable sums have been saved by servicing, modifying, and constructing other instruments for the laboratories outwith the immediate remit of Technicon maintenance. Other economic and operational benefits which result from the scheme are commercially disinterested advice on equipment obsolescence and replacement, and redistribution between the laboratories of old but useful equipment to meet specific needs of the service in the region.

Autoanalysis↗
PubMed1979

The effect of indomethacin on the biochemical response to fracture stress in rats.

After acclimatization to metabolic cages, groups of male Wistar rats were pretreated for 48 h with parenteral indomethacin to observe its effect on the biochemical response to femoral fracture stress. This trauma induced an average 2.3-fold rise in fibrinogen levels in all animals, which was maximal 24 h after injury. Indomethacin pretreatment caused a dose-related decrease in the plasma fibrinogen response 24 h after fracture: 1, 2, 10 or 20 mg/kg/day of drug reduced the response by approximately 3, 10, 13 and 23%. Fibrinogen levels in rats treated with high doses (10 and 20 mg/kg) of drug began to rise before fracture owing to intestinal ulceration. Plasma 11-hydroxycorticosteroids and urine total catecholamine levels did not respond to either indomethacin treatment or to fracture but levels of both compounds rose gradually during the experiment. Indomethacin is an inhibitor of prostaglandin synthesis and prostglandins may therefore be involved in the metabolic response to stress.

11-Hydroxycorticosteroids↗
PubMed1978

Chemical and kinetic study of the lipoproteins in abetalipoproteinaemic plasma.

Abetalipoproteinaemic plasma lipoproteins were fractionated by molecular sieve chromatography into two classes on the basis of size. Each class had the same chemical and immunochemical composition and seemed to be interconvertible in vitro, presumably as a result of aggregation/disaggregation. The low levels of circulating apolipoprotein A-I found in abetalipoproteinaemic subjects have been shown by kinetic analysis to result from reduced synthesis of the apoprotein and not from increased catabolism or redistribution between vascular and extravascular compartments.

Abetalipoproteinemia↗
PubMed1978

A limited protocol for assessment of within-batch performance of multichannel analysers.

An experimental protocol is described to evaluate rapidly the performance of biochemical analysers. A trial in which this protocol was applied to 15 multichannel continuous-flow analysers is described and the results are discussed. Some consideration is given to the effects of applying a commonly-used drift correction procedure to the raw data, and values of within-batch standard deviation are proposed which may be useful in assessing performance.

Autoanalysis↗
PubMed1978

Optimal conditions for the estimation of ammonium by the Berthelot reaction.

A technique for optimising reagent concentrations on the AutoAnalyzer has been applied to the estimation of ammonia by the Berthelot reaction in the determination of urea and organic nitrogen. Comparison of the use of phenol and salicylate revealed that the optimum concentration of the latter is about four times that of the former. The optimum concentration of hypochlorite is five times greater with salicylate than with phenol, and for the catalyst, sodium nitroprusside, the factor is two. The precision obtained with the different methods is similar.

Ammonia↗
PubMed1978

Drift correction--a comparative evaluation of some alternatives.

Three drift correction methods are described. The results obtained from computer simulation of these methods and their application to raw data obtained from a survey of multichannel continuous-flow analysers are discussed, with particular reference to the effects of each method on analytical precision and accuracy, and on between-analyser variation. A geometrically derived method of drift correction was found to be the most satisfactory.

Autoanalysis↗
PubMed1975

Variations in mechanical sampling: their causes and effects.

Three characteristics of a sample of AutoAnalyzer Sampler II modules have been measured: eccentricity of the cam, eccentricity of the spindle driving the cam, and the lengths of the chords of the cam lobes. Imprecision in timing may make a significant contribution to analytical error.

Autoanalysis↗