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Biomedical subjects

A Fleck

Publications and source records attributed to A Fleck.

At least 37 records · Page 2Linked to original sources
PubMed1988

Observations on the delay in onset of the acute phase protein response.

The early time course of the acute phase protein response (APPR) and mediators involved in its control were investigated in the rat and mouse. After turpentine-induced inflammation in the rat C-reactive protein and fibrinogen increased in concentration peaking at 48 h and 18-24 h, respectively. A 9 h delay prior to elevation of these protein was observed. After injection of endotoxin into mice, a 4-6 h delay was observed prior to any increase in the concentration of the acute phase protein serum amyloid P-component. This delay was shortened to 2 h after injection of leucocytic endogenous mediators (LEM) produced from rabbit peritoneal exudate cells. It is concluded that the delay between the initiating stimulus and the increases in the acute phase proteins is due to some obligatory intermediate steps which lead to the production of the final mediators of the APPR, and that these mediators are present in LEM.

Acute-Phase Reaction↗
PubMed1985

Pocket computers: a new aid to nutritional support.

A program has been written to run on a pocket computer (Sharp PC-1500) that can be used at the bedside to predict the nutritional requirements of patients with a wide range of clinical conditions. The predictions of the program showed good correlation with measured values for energy and nitrogen requirements. The program was used, with good results, in the management of over 100 patients needing nutritional support. The calculation of nutritional requirements for each patient individually facilitates more appropriate treatment and may also produce financial savings when compared with administration of a standard feeding regimen to all patients.

Adolescent↗
PubMed1985

Increased vascular permeability: a major cause of hypoalbuminaemia in disease and injury.

The rate of loss of albumin to the tissue spaces (measured as transcapillary escape rate) rose by more than 300% in patients with septic shock, and the average increase within 7 h of cardiac surgery was 100%. The transcapillary escape rate in cachectic cancer patients was twice that of a group of healthy individuals. The rate of loss of albumin to the tissue spaces is normally 5%/h, which is more than 10 times the rates of synthesis and catabolism, and these large rate increases indicate that increased vascular permeability is an important cause of the lowered concentration of albumin commonly seen in acute and chronic disease.

Capillary Permeability↗
PubMed1984

Early plasma protein and mineral changes after surgery: a two stage process.

Sequential changes in albumin, transferrin, alpha 1-acid glycoprotein, C reactive protein, fibrinogen, copper, iron, and zinc in plasma up to 24 h after hysterectomy were measured. No increases in the concentrations of the acute phase proteins alpha 1-acid glycoprotein, C reactive protein, and fibrinogen were observed until 6 h after the skin incision. These increases were preceded by significant falls at 2-4 h, and this was shown also by albumin, transferrin, iron, zinc, and copper. The ratios of iron and zinc to their binding proteins, transferrin and albumin, did not decrease until 4-6 h and their concentrations remained low for at least 24 h. These patterns suggest that at least two mechanisms operate after trauma. The early fall in the concentrations of the proteins in plasma is consistent with a prompt increase in microvascular permeability. The later decrease in binding of the metals iron and zinc to their transport proteins and the increase in concentrations of the acute phase proteins could be initiated by a common mediator.

Adult↗
PubMed1984

Simplified analytical methods for the measurement of the synthesis rate of plasma proteins in vivo by the [14C]carbonate method.

We describe a method for obtaining the specific activity of 14C in urea, essential in the measurement of the synthesis rate of a plasma protein in vivo, which is simpler than the original procedure. The principle is the measurement of 14CO2 and NH4+ separately, after incubation with urease. A simple alteration gives samples of 13CO2 for mass spectrometry. The 'recoveries' of 14C and 13C in urea were invariably between 90 and 96% and the CV was 3%.

Ammonia↗
PubMed1983

Early time course of the acute phase protein response in man.

The rate at which the acute phase protein response occurred after both major and minor surgery was explored. Increases in the plasma concentration of C-reactive protein (CRP), alpha-1-acid glycoprotein (alpha 1 AG) and fibrinogen were not detected until 6-8 h after the initial incision. The peak concentration of CRP occurred at 48 h and that of fibrinogen at 96 h; alpha 1 AG concentrations rose rapidly until 48 h followed by little change until about 120 h. Although there was widespread variation in the concentrations of individual proteins in patients, severity of injury did not seem to have a significant effect on the time course of the change. Plasma cortisol concentration and the total white blood cell count (WBC) reached their peaks before the acute phase proteins, cortisol at 6 h and WBC at 12 h.

C-Reactive Protein↗
PubMed1982

Temperatures used in the determination of enzyme activity in clinical biochemistry laboratories in Britain: results of a survey.

Information on the temperature used in the determination of enzyme activity in clinical biochemistry laboratories in Britain was obtained by circulating a questionnaire to 400 laboratories in Britain. Replies were analysed from 321 laboratories (80%). A large majority of laboratories use 37 degrees C to determine enzyme activity: 99% use this temperature for amylase, 88% for alkaline phosphatase, and 81% for aspartate and alanine amino-transferases. A greater proportion of laboratories with large workloads use 37 degrees C than do those with smaller workloads. The majority of laboratories use equipment with incubation temperatures that are selectable within the laboratory. When there is evidence of advantage in using a particular temperature most laboratories use this temperature. Almost one-quarter of the laboratories replying participate in a local agreement to use 37 degrees to determine enzyme activity. About one-third of laboratories consider it impracticable to change to 30 degrees C, and of those replying to the question on whether they were willing to change to 30 degrees C, 49% indicated that they were not willing to do so.

Alanine Transaminase↗
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↗