Effect of short term triiodothyronine administration on human leukocyte Rb(K) influx and Na efflux.

The effect of short term T3 administration on leukocyte ouabain-sensitive 86Rb(K) influx and Na efflux in normal subjects was investigated. At a dose of 60 micrograms daily for 7 days, T3 induced a significant increase in leukocyte 86Rb(K) influx and a significant fall in plasma K concentrations. Plasma and intracellular Na concentrations did not change. [3H]Ouabain binding, a measure of Na-K ATPase units, did not change. A week after T3 administration, 86Rb(K) influx, Na efflux, and plasma K concentrations were normal. In a series of five hyperthyroid patients, both ouabain-sensitive 86Rb influx and [3H]ouabain binding were significantly greater than in normal subjects. We conclude that T3 stimulates 86Rb(K) influx and Na efflux by leukocytes in vivo independently of [3H]ouabain binding and that this increase is rapidly reversible. However, in hyperthyroid patients both 86Rb influx and [3H]ouabain binding are increased, probably due to prolonged exposure to thyroid hormone excess.

The acute in vitro effect of ethanol, its metabolites and other toxic alcohols on ion flux in isolated human leucocytes and erythrocytes.

Using isolated healthy human leucocytes and erythrocytes as model cells, we investigated the inhibitory effect of ethanol, its metabolites and of other toxic alcohols on the active fluxes of rubidium (Rb: equivalent to K) and sodium (Na), and on Na,K-ATPase activity. Ethanol (80 mmol X l-1) inhibited total and ouabain-sensitive 86Rb influx and 22Na efflux in leucocytes, this being dose-related for total, ouabain-sensitive and ouabain-insensitive fluxes at higher concentrations. In erythrocytes inhibition occurred at 20 mmol X l-1 for 86Rb influx, dose-related at higher concentrations as for leucocytes. 22Na efflux was inhibited at 80 mmol X l-1 and above. Acetaldehyde (0.1 and 0.2 mmol X l-1), 1,2-propanediol (0.8 mmol X l-1) and 2,3-butanediol (0.4 mmol X l-1) inhibited all fractions of 86Rb influx in erythrocytes, but not in leucocytes. Methanol, 2-propanol and 1,2-ethanediol (16 and 32 mmol X l-1) inhibited 86Rb influx in erythrocytes, but not in leucocytes. The order of potency was 2-propanol greater than 1,2-ethanediol greater than methanol. Na,K-ATPase activity was inhibited in lysed leucocyte and erythrocyte preparations only at very high concentrations of the alcohols--suggesting that inhibition is due to an alteration in membrane structure and not to a direct effect on the enzyme.

Training and organization for pathology in Britain. The role of chemical pathologists.

In Britain, the term "clinical pathology" indicates the discipline of pathology applied to patients, whereas "chemical pathology" refers to pathology in its chemical and biochemical aspects, both as a basic science and for patient care. The initial training of a chemical pathologist is usually in general pathology, in metabolic medicine, or in research. This training continues solely in chemical pathology, and the specialist qualification, namely Membership of the Royal College of Pathologists, is taken at about 32 years of age. Training is similar in the other disciplines of pathology, and a pathologist usually achieves a senior permanent appointment by the age of 34 years. By national policy, pathology laboratories, each with departments of chemical pathology, hematology, histopathology, and microbiology, are centered in about 250 District General Hospitals. The chemical pathology section ideally includes both a medical consultant and an equivalent non-medical scientist. These ideals are unlikely to be reached because of pathologists usually include laboratory supervision, clinical liaison, teaching, and research. Many chemical pathologists also have specific clinical consultant activities, such as overseeing a Metabolic Unit.

Training and career appointments in the pathological sciences in the United Kingdom.

Pathologists usually receive initial training in clinical work, or in general pathology, or in academic work, followed by speciality training as a senior registrar or lecturer. Consultant status is generally achieved by the age of 34, now almost always in a single discipline. The distribution of pathologists between disciplines, in National Health Service and university posts, is tabulated: there are many unfilled appointments.

Medical careers in pathology, 1977.

A survey has been made, mainly covering the second half of 1977, of career grade posts and senior training posts in pathology in the United Kingdom. The survey included all disciplines of pathology and all types of employment--National Health Service, medical school, and many others. The survey also examined the number of applicants for advertised posts and the number of posts left vacant. There were variations between disciplines and between regions; microbiology and Northern Ireland had most failures in filling posts. Overall about 3% of career grade posts, and 15% of training grade posts, were left unfilled.

Plasma alkaline phosphatase isoenzymes in hepatobiliary disease.

BY CELLULOSE ACETATE OR ACRYLAMIDE GEL ELECTROPHORESIS IT IS POSSIBLE TO SEPARATE THESE ALKALINE PHOSPHATASE ISOENZYMES FROM SERUM: [anode] fast liver, slow liver, placenta/Regan, bone, intestine, bile [cathode]. Heat or chemical inhibition can confirm the differentiation. Normal adult serum always contains slow-liver isoenzyme, and sometimes bone isoenzyme: the latter is always present in serum of children. In hepatobiliary disease slow-liver isoenzyme was always increased: intestinal isoenzyme appeared in many cases of cirrhosis (of blood groups B and 0) but fast-liver and bile isoenzymes were occasionally seen in miscellaneous cases. The findings in other diseases included Regan isoenzyme in six out of 45 cases of malignant disease.

Electrophoretic separation and differentiation of enzymes from human and from porcine liver.

The electrophoretic separations of some human and pig liver enzymes on cellulose acetate and Cellogel were investigated, with reference to their joint occurrence in serum of patients undergoing treatment by extracorporeal pig liver perfusion. In every case it was possible to distinguish between the human and pig enzymes. Pig lactate dehydrogenase isoenzymes occupy a position slightly anodic to the corresponding human bands. The aspartate transaminase band of human is more anodic than that of pig, but their cathodic bands have the same mobility. Alanine transaminase of both human and pig liver extract is shown to exist as two bands each towards the anode. The faster moving human band is more anodic than the corresponding pig band, while the other human band is less anodic. Sorbitol dehydrogenase, alkaline phosphatase, and ornithine carbamoyltransferase all exist as one band each. Human sorbitol dehydrogenase is more cathodic than the pig enzyme, human alkaline phosphatase more anodic than the pig enzyme, while human ornithine carbamoyltransferase is less anodic than the pig enzyme.

Serum copper: a marker of disease activity in rheumatoid arthritis.

Serum copper concentrations were measured in patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), osteoarthritis (OA), and in healthy controls. Median serum copper concentrations were raised significantly in RA and AS, but not in OA. Serum copper in RA correlated significantly with a number of disease activity markers--for example erythrocyte sedimentation rate (ESR), C-reactive protein, haemoglobin concentration, morning stiffness, and grip strength. It also correlated well with the overall disease activity as assessed by a composite index. Raised serum copper was associated with severe RA as manifested by the presence of immunoglobulin M rheumatoid factor, extra-articular features, weak grip and highly active disease. High serum copper might be related to the development of the pathological lesions observed in RA and not just be a secondary response.

A fluorimetric and enzymatic method for the estimation of serum total bile acids.

The enzymatic technique using 3alpha-hydroxysteroid dehydrogenase for determining bile acids in blood has been modified by measuring the reduced nicotinamide adenine dinucleotide fluorimetrically. The increased sensitivity attained enables the concentration of total bile acids in serum to be estimated using 3 ml for normal subjects and 1 ml for jaundiced patients. The range of normal values in serum was found to be 0-4.7 mumol/litre for males and 1.0-8.2 mumol/litre for females.

An AutoAnalyzer method for estimating serum glyceride glycerol using a glycerokinase procedure.

THE GLYCERIDE GLYCEROL ANALYSIS DEPENDS, AFTER SAPONIFICATION OF TRIGLYCERIDES, ON A LINKED ENZYMATIC PROCEDURE USING GLYCEROKINASE, PYRUVATE KINASE, AND LACTATE DEHYDROGENASE: the final conversion of NADH to NAD(+) is followed fluorimetrically. Twenty analyses can be performed per hour on the AutoAnalyzer; recoveries of added triglycerides ranged between 90 and 104%. In a mixed male and female group the normal range for glyceride glycerol was 2.5 to 15.5 mg/100 ml (0.2-1.4 mmol/l) fasting, and 2.5 to 18.0 mg/100 ml (0.2-1.6 mmol/l) postprandially using fresh serum. There was a significant rise postprandially in older men.

Ultramicrofluorimetric determination of calcium in plasma.

A precise and reproducible method is described for the ultramicro fluorimetric determination of calcium in plasma, based upon the formation of a fluorescent complex between calcium and calcein at a strongly alkaline pH. In a group of normal subjects, the mean concentration of plasma calcium was 9.66 mg/100 ml with a normal range of 8.9 to 10.4 mg/100 ml.

Effect of glucose intake on human leucocyte 86Rb influx and [3H]-ouabain binding.

86Rb influx and [3H] ouabain binding by human leucocytes were measured in eight normal nonobese fasting subjects before and after a challenge with 75 g glucose orally. The mean ouabain-sensitive 86Rb influx increased significantly from 194 to 283 mmol/kg protein/h (P less than .01), and [3H]-ouabain binding increased from 236 to 403 fmol/mg protein. The mean plasma potassium concentration fell from 4.2 to 3.9 mmol/L (P less than .05). Following intravenous glucose infusion, the median 86Rb transport increased from 186 to 267 mmol/kg protein/h, while median plasma potassium concentration fell from 4.3 to 3.9 mmol/L. Therefore, glucose intake acutely increases Na-K ATPase units, stimulates potassium (Rb) transport, and causes a concomitant fall in plasma potassium concentrations. Nutritional intake is probably an important determinant of Na-K ATPase units and activity in the human leucocyte.

Increased leucocyte Na-K ATPase in obesity: reversal following weight loss.

Ouabain-sensitive 86Rb influx and [3H] ouabain binding capacity were investigated in the leucocytes of 17 obese patients and 15 control subjects. Both were significantly increased in the obese when compared with controls. Following dietary restriction and a 4% to 5% weight reduction in the obese over 2 weeks, [3H] ouabain binding and ouabain-sensitive 86Rb influx (a model for K+ influx) decreased to levels similar to those in controls. This shows that the number of Na-K ATPase sites on leucocyte membranes of the obese are significantly increased and that this is associated with accelerated 86Rb transport. Since both of these indices decreased following 4% to 5% reduction in body weight while the patients were still obese, increased Na-K ATPase is neither a marker of nor cardinal to the pathogenesis of obesity. We conclude that (1) increase in Na-K ATPase units and 86Rb influx are not characteristic of obesity itself and (2) dietary restriction over the short-term with limited weight reduction restores Na-K ATPase units and 86Rb influx to normal.

Effect of beta-blockade and subsequent triiodothyronine administration on human leucocyte Na-K ATPase.

We have investigated the effect of beta-blockade and beta-blockade + triiodothyronine (T3) administration on 86Rb (K) influx and [3H]-ouabain binding by human leucocytes and on plasma potassium concentrations. beta-blockade with nadolol (40 mg daily) for five days resulted in a significant decrease in 86Rb influx and [3H]-ouabain binding, as well as an increase in plasma potassium concentration. T3 administration thereafter caused a fall in plasma concentration and an increase in 86Rb influx. There was a tendency toward restoration of [3H]-ouabain binding to normal. The fact that beta-blockade inhibits 86Rb (K) influx and increases plasma potassium concentration implies that endogenous adrenaline exerts a tonic stimulatory effect upon 86Rb (K) influx and a suppressive effect on plasma potassium concentrations in vivo. T3 administration induces an increase in 86Rb (K) influx and a fall in plasma potassium concentrations. This suggests that either the effect of T3 is independent of beta-adrenoceptors or that the known increase in beta-adrenoceptor population secondary to T3 administration increases sensitivity to circulating adrenaline in spite of beta-blocker administration.

Radial presentation of results of blood acid-base analyses.

Both students and clinical users find interpretation of blood acid-base numerical values to be difficult. A radial plot provides patterns which are easy to understand, and which can be applied to many groups of laboratory results.

Wellcome lecture 1986. Ideas towards a general theory of clinical biochemistry.

Clinical biochemistry, as an independent discipline within medical science, has developed its own body of theory and practice, and as such it cannot only be concerned with collecting observations. A simple report (plasma potassium = 5.3 mmol/L) is used as a model to discuss the problems of understanding measured chemical changes in the body in disease, and how these lead towards a general theory. These include the nature of the analysand and the reference base; accuracy and identification of the analyte; how disturbances of the steady state contribute to changes in a static result; the implications of precision; differences between activity, concentration and content; the convention of arithmetical concentration; and the meaning of 'abnormal', and of derived terms such as 'predictive value' and 'decision level'. Clinical biochemists/chemical pathologists, with their understanding of all these and related problems, must act as the necessary bridge between analysts and clinicians.