bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Aspects of the Need for High Capacity Analysis
Authors: Watts R. W. E.
Published: February 2014

Acceptable standards of medical and surgical diagnosis and treatment depend upon the ready availability of high capacity chemical analysis. This need is expanding and there are valid reasons for believing that it will continue to do so. The present and future needs arise from clinical problems. The efflorescence of clinical chemistry during the past two decades has resulted from these problems and not from autonomous growth which then stimulated further demands from the bedside. The application of chemistry to medicine presents special problems in the fields of: (1) data interpretation, (2) data handling, (3) the need to incorporate a wide ranging consultative function into the system. Adaptability as well as new instruments will be needed in laboratory and clinical practice if we are to meet our patient's needs as clinicians and as laboratory workers.
Evaluation of the IL 368 Clinicard Analyser
Authors: Taylor J. , Bell Joyce L.
Published: February 2014

An assessment of the performance of the IL 368 Clinicard Analyser is given. The methods tested were urea, sugar, bilirubin, aspartate transaminase and creatine kinase. Overall a good precision and correlation with the routine laboratory methods was found. The machine should prove useful for the analysis of frequently requested emergency determinations.
Screening for Paracetamol Poisoning
Authors: Simpson E. , Stewart M. J.
Published: February 2014

The commonly used tests for the detection of paracetamol or its metabolites in cases of self-poisoning are either non-specific or time consuming. The need for screening all cases of self-poisoning for paracetamol ingestion is emphasised and a test is recommended which combines the advantages of increased specificity with those of a short procedure.
The Use of a Reflectance Meter in the Diagnosis of Neonatal Hypoglycaemia
Authors: Baxter R. H. , Logan R. W.
Published: February 2014

Experience with a Reflectance Meter in the diagnosis of neonatal hypoglycaemia is described. A good correlation was found between glucose concentrations measured by the meter and by a standard automated glucose oxidase method (p < 0.001) but the meter gave significantly lower values (p < 0.02) than the automated method, an effect which was independent of the packed cell volume.
Iodine Contamination in Iodometric Measurements of Thyroid Hormones
Authors: Cusick C. F.
Published: February 2014

The incidence of iodine contamination in serum protein-bound iodine requests was assessed by comparison of results with those of a method using anion-exchange columns to improve specificity. The precision, accuracy, and specificity of the column method was found to be adequate, abnormal elution patterns generally warning where results were affected by contamination. The proportion of discrepancies in results and diagnoses between the two tests showed the protein-bound iodine to be unsatisfactory as a sole test of thyroid hormone levels, or in hypothyroidism, even as a screening test.
Body Composition in Alcoholic as Compared to Control Individuals
Authors: Shaw D. M. , Tidmarsh S. F. , MacSweeney D. A. , Johnson A. L. , Godfrey B. E. , Allan D. J. , Merry Julius
Published: February 2014

Height, weight, total body potassium, exchangeable sodium, bromide space, total body water, and concentrations of sodium, potassium, and chloride in plasma were measured in control subjects and individuals suffering from alcoholism, with techniques which included body counting and a multiple isotope method using 24Na, 82Br and 3HzO.

No differences were found between control and alcoholic subjects so there was no evidence that chronic alcoholism altered body composition. In particular, there was no evidence of cellular damage or loss which would have been reflected in changes in KT or KIN. The data were combined and were analysed to give information on the relationships of the variates.
A Critical Evaluation of Separation Methods in Radiommunoassays for Total Triiodothyronine and Thyroxine in Unextracted Human Serum
Authors: Ratcliffe W. A. , Challand G. S. , Ratcliffe J. G.
Published: February 2014

Methods for separating free and antibody-bound hormone in radioimmunoassays for total triiodothyronine (T-3) and thyroxine (T-4) in unextracted human serum are evaluated. For T-3 assay, a simplified second antibody technique has significant advantages over other methods and gives a mean interassay coefficient of variation of 7.2 % over a wide range of values. For T-4 assay, polyethylene glycol is the method of choice and has a mean interassay coefficient of variation of 4.7 %. By adding the separating agents initially, the assays are readily semi-automated and may be completed within a working day.
SI Units: How Systematic and How International are They?
Authors: McLauchlan D. M. , Raggatt P. R. , Zilva Joan F.
Published: February 2014

Despite the fact that the use of SI units should standardize the reporting of results in chemical pathology, there is still considerable confusion in some areas about the accepted conventions. This confusion is particularly rife in reporting results of thyroxine, and, to a lesser extent, of lipid assays.
Development and Evaluation of a Six-Channel Automated Analyser for 24-h Urine Specimens
Authors: Hirst A. D. , Howorth P. J. N.
Published: February 2014

A system has been developed for the analysis of 24-h urine collections for sodium, potassium, calcium, phosphate, urea, and creatinine, using a six channel AutoAnalyzer for the analysis, and a computer for calculating the results and producing cumulative reports.
Factors Affecting the Release of Haemoglobin and Enzymes from Human Erythrocytes
Authors: Wilkinson J. H. , Robinson Jean M. , Johnson K. P.
Published: February 2014

The efflux of lactate dehydrogenase and haemoglobin from human erythrocytes during prolonged incubation at 37° was significantly reduced by ATP, ADP, AMP, UTP, creatine phosphate, or phosphoenolpyruvate and to a lesser extent by fructose, glucose 6-phosphate or fructose 6-phosphate, but not by glucose. Iodoacetate, however, markedly increased the loss of haemoglobin and slightly increased that of lactate dehydrogenase.

Phospholipase C greatly accelerated the relase of haemoglobin, lactate dehydrogenase, pyruvate kinase, hexokinase, glucose 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase from human erythrocytes, but this effect was also reduced in the presence of ATP or ADP. The loss of lactate dehydrogenase, malate dehydrogenase, and pyruvate kinase from the cells treated with phospholipase C increased as their ATP content fell. In a series of experiments in which the action of phospholipase C was stopped by the subsequent addition of trypsin, ATP and ADP (1 mmol/l) significantly reduced the efflux of haemoglobin, but AMP had no such effect.

The results are consistent with the conclusion from our previous work that enzyme leakage is related to diminution in the energy content of the cells. The protective action of AMP on cells not treated with phospholipase C, however, differs from earlier findings with rat lymphocytes and it is suggested that in red cells it might be converted into ATP or that it has a direct effect on the permeability of the cell membrane.
Assessment of a Simple Competitive Protein-Binding Technique for Plasma Cortisol Assay
Authors: Crowley Mary F. , Garbien Katherine J. T. , Tuttlebee J. W.
Published: February 2014

The Cortipac kit for Cortisol assay by a competitive protein-binding technique (CPB) which utilizes 75Se Cortisol has been evaluated. Results obtained by it agree well with those by the Mattingly fluorimetric method. Assays can be carried out on either plasma or serum and haemolysis does not interfere. The specificity of the assay was checked in blood samples from patients receiving synthetic steroids. Prednisone and prednisolone therapy caused significant interference with the assay; fluorocortisol and dexamethasone therapy did not. The increased progesterone in late pregnancy blood samples had only a small effect on the assay. Plasma samples for Cortisol assay could be stored for at least 4 weeks at 4°C and for at least 12 weeks at −20°C.
The Performance of the ‘Centrifichem’ Parallel Fast Analyser Using Packaged Reagents
Authors: Henry P. , Saunders R. A.
Published: February 2014

The CentrifiChem system was used with packaged reagent kits for the following determinations: albumin, alanine and aspartate aminotransferases, creatinine, glucose, and α-hydroxybutyrate and lactate dehydrogenases. The linearity obtainable for each assay was investigated, and particular attention was paid to finding the most suitable instrument settings.
Variations in Mechanical Sampling: Their Causes and Effects
Authors: McLelland A. S. , Fleck A. , Wagstaff D. , Robinson R.
Published: February 2014

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.
Why Measure Blood Barbiturates?
Authors: Simpson Elliott , Stewart Michael
Published: February 2014

Phenobarbitone levels in the blood do not always provide a reliable guide in the management of the poisoned patient. They may rise in response to active treatment though the patient may be improving clinically. Some reasons for this are considered, with illustrations from three cases. It is concluded that the poor correlation of phenobarbitone levels with a patient's condition is due not to inadequate analytical techniques but to the poor representation of the “whole body” situation by a single blood specimen. The usefulness of analysing such specimens is questioned.
Problems in the Development of New Instruments
Authors: Riley Clifford
Published: February 2014

Despite the complexity of much modern apparatus the responsibility for inventing new equipment still rests with the scientist. A high level of practical skill is not necessary, but working models play a valuable part. The instrument industry has an equally essential part to play in converting an innovation into a viable commercial product and must take great financial risks in doing so.
Glycosaminoglycan Fractions in Normal Human Urine
Authors: Pennock C. A. , Charles R. G. , Stansbie D.
Published: February 2014

A study has been made of glycosaminoglycans in normal urine to determine which are non-dialysable, which are ultrafilterable, and which are precipitable with cetypyridinium chloride or alcohol.

The main fractions present in human urine are: (1) High molecular weight material which is non-dialysable and precipitated by alcohol and by cetylpyridinium chloride. (2) High molecular weight material which is non-dialysable and precipitated by alcohol but not by cetylpyridinium chloride. (3) Low molecular weight material which is ultrafilterable and precipitated by alcohol and by cetylpyridinium chloride. (4) Low molecular weight material which is ultrafilterable and precipitated by alcohol but not by cetylpyridinium chloride.

The heavy losses of glycosaminoglycans on dialysis have led us to conclude that this method should not be used to study the excretion of these polymers and that direct precipitation with cetylpyridinium chloride, which can be used to isolate both non-dialysable and ultrafilterable macromolecular fractions relevant to the diagnosis of the mucopolysaccharidoses, is the method of choice.
An Investigation into the Automated Measurement of Urinary Oestrogens in Pregnancy
Authors: Simkins A. , Worth H. G. J.
Published: February 2014

Changes in the relative sensitivity of reaction of oestrone, oestradiol, oestriol, and their monoglucuronides due to changes in reaction temperature and the acid and quinol concentrations of Kober's reagent have been investigated by means of an automated system. Similar investigations have been carried out with a number of standardized pregnancy urines. All measurements have been made with reference to an oestriol-16α(β-D-glucuronide) standard. These changes have been examined with trichloracetic acid and p-nitrophenol in Ittrich's reagent. The importance of the final acid concentration has also been examined. As a result of these investigations a modified scheme is suggested which gives maximal sensitivity to oestriol conjugates and minimal sensitivity to oestradiol conjugates, and may be calibrated by using an oestriol conjugate as a primary standard. The effect of varying the concentration of trichloracetic acid and p-nitrophenol in Ittrich's reagent has been examined under these modified conditions. More than 200 urines have been assayed by this method and the results compared with those obtained by the present automated procedure. The effect of dilution on many of these specimens has also been examined.
Separation and Relative Quantitation of Lipoproteins by Polyacrylamide Gel Disc Electrophoresis
Authors: Maddock Claire , Billimoria J. D.
Published: February 2014

Electrophoresis of lipoproteins by Polyacrylamide gel disc electrophoresis is described and a quantitation of the pattern obtained in normal subjects in terms of the “esterified fatty acid index” is compared with similar patterns on paper and cellulose acetate electrophoresis.
A New Look at the Measurement and Interpretation of Enzyme Assays
Authors: Ceriotti Giovanni
Published: February 2014

Some methodological problems in clinical enzymology, including instability of enzymes in the incubation mixture and requirements for optimal reaction conditions, are highlighted. The importance of a knowledge of fundamental enzyme biochemistry and physiology as the basis for their diagnostic application is stressed, and the different behaviour of some hepatic enzymes—namely, GOT, GPT, γ-GT, and OCT, in various pathological conditions is traced back to their characteristic biochemical and physiological properties. In the field of urinary enzymes a knowledge of the ideal requirements for the enzyme investigation of the various renal functions and of the properties of potentially valuable enzymes permits a critical selection of the really useful ones.
Preparation of 125I-thyioxine and 125I-triiodothyronine of High Specific Activity for the Radioimmunoassay of Serum Total T4 and T3
Authors: Thurlow Vanessa R. , Puxley Hilary J.
Published: February 2014

A simple and inexpensive procedure for the preparation of high specific activity 125I radioiodinated triiodothyronine and thyroxine is described. The specific activities achieved are approximately 350 Ci/g for 125I-T4, and either 220 Ci/g or 500 Ci/g for 125I-T3 depending on the reagents employed. The high specific activity 125I-T4 and 125I-T3 are suitable for the routine radioimmunoassay of serum total T3 and T4. When properly stored they have a shelf life of at least seven weeks.
How to Pass Examinations: A Personal View on Good Technique in Clinical Biochemistry Examinations
Authors: Bold Alan M.
Published: February 2014

Elementary faults in examination technique are commonly displayed by candidates who have worked hard for the examination. Advice is offered on answering multiple-choice questions and “essay” questions and on how to tackle oral and practical examinations. A candidate's preparation for an examination should include the submission of written work and the taking of a mock oral examination for critical assessment by a supervisor.

Careful writing up of practical work in the home laboratory is important, so that faulty technique can be corrected early in training. Above all, stress is laid on the importance of mastering the technique of effective communication for success both in examinations and in later professional life.
Rapid Determination of Plasma Paracetamol
Authors: Wilkinson George Stanley
Published: February 2014

A simple colorimetric method for the determination of plasma paracetamol in emergency cases of overdose is described. A comparison with an ultraviolet method was performed.
Evaluation of a Serum/Plasma Separator: Suitability of Samples for Radioimmunoassay and Competitive Protein Binding Techniques
Authors: Garbien Katherine J. T. , Tuttlebee J. W. , Crowley Mary F.
Published: February 2014

A new method of separating serum or plasma from whole blood (Sure-Sep, W. R. Warner) has been evaluated with particular regard to the suitability of the serum/plasma samples for radioimmunoassay (R.I.A.) and competitive protein binding (C.P.B.) techniques. Sure-Sep did not affect the results obtained for the following assays: cortisol, thyroxine, triidothyronine, insulin, and growth hormone. In addition it was also found that contact of the serum or plasma samples with Sure-Sep for 24 hours at 4°C was without effect on the results obtained.
Determination of Bilirubin in Amniotic Fluid: A Comparison of Some Current Methods
Authors: Simkins A. , Worth H. G. J.
Published: February 2014

Three methods for the estimation of bilirubin in amniotic fluid are compared. The within-batch precision and recovery of bilirubin by each method has been studied, and the effects of the presence of haemoglobin, methaemoglobin, and methaemalbumin in varying concentrations have been investigated. Measurements on amniotic fluid from patients with rhesus isoimmunization have also been compared and regression equations calculated. The results of the three methods agree reasonably well so long as no haemoglobin degradation products are present. It is suggested that in the presence of these products a method involving organic solvent extraction of bilirubin gives the most accurate result.
Regulation of Calcium Metabolism
Authors: Russell R. G. G.
Published: February 2014

This paper reviews the regulation of calcium metabolism in man. The body's calcium economy is determined by the relationship between the intestinal absorption of calcium, the renal handling of calcium, and by the movements of calcium in and out of the skeleton. These processes are influenced by many factors, the most important of which are parathyroid hormone and the hormones derived from the renal metabolism of vitamin D, notably 1,25-dihydroxyvitamin D8. The role of endogenous calcitonin in man is still controversial, but there are several other hormones which have some influence on calcium metabolism, including thyroid hormone, growth hormone, and the adrenal and gonadal steroids. Clinical disorders of calcium metabolism and their treatment are discussed in terms of the disturbances in normal physiology they represent.
Enzymatic Determination of Cholesterol and Triglyceride with the Abbott Bichromatic Analyser
Authors: Barbour Heather M.
Published: February 2014

Enzymatic methods for cholesterol and triglycerides on the Abbott Bichromatic Analyser are compared with standard non-enzymatic assays. Factors affecting the performance of the ABA 100 and precision of the enzymatic assays on this instrument are discussed.
A Comprehensive Screening Method for Detecting Organic Acidurias and other Metabolic Diseases in Acutely Sick Infants and Children
Authors: Chalmers R. A. , Watts R. W. E. , Lawson A. M.
Published: February 2014

A protocol is described for the comprehensive screening of acutely ill neonates and infants for inherited metabolic diseases, with particular reference to the organic acidurias. A group of simple initial tests provide positive pointers to metabolic disorders, leading to comprehensive screening tests for the aminoacidopathies and organic acidurias. Specimen chromatograms of urinary organic acids in the normal neonate, infant, and child, obtained using the methods described, are given and compared with that from the urine of a child with previously unreported 2-hydroxyglutaric aciduria. The place of the scheme in the management of inherited metabolic disease in the perinatal period and its relationship to other screening programmes are discussed. It is estimated that use of the protocol would allow the detection of about one-half of the known inborn errors of metabolism, including the aminoacidopathies, the organic acidurias, the hyperammonaemias, and several disorders of carbohydrate metabolism, many of which present acutely in the neonate and infant.
Some Problems in the Correction for Intrinsic Light-Scattering of Samples in Specific Protein Analysis by Automated Immunoprecipitation
Authors: Shenkin A. , Morrison Barbara , Robertson D. A.
Published: February 2014

Heparinised plasma samples have falsely high blank values in the automated immunoprecipitation system when blanks are measured by omitting antiserum from the assay. This is probably due to an interaction of heparin and serum proteins, together with either fibrinogen or polyethylene glycol. A more accurate estimate of the blank of heparinised plasma samples is obtained by measuring it with a solution of nonimmune serum substituted for the antiserum.
Therapeutic Comparison of Thiol Compounds in Severe Paracetamol Poisoning
Authors: Solomon Anne E. , Briggs J. D. , Knepil J. , Henry D. A. , Winchester J. F. , Birrell R.
Published: February 2014

Twelve patients with toxic blood concentrations of paracetamol were treated with either cysteamine or amino-acid solution. None of the patients developed severe liver damage, although transient mild biochemical abnormalities developed in three. None of the patients treated with amino-acid solution had side effects due to therapy, whereas all those treated with cysteamine did. It is recommended that amino-acid solutions be used as a temporary measure in patients suspected of massive paracetamol overdose while awaiting estimation of blood paracetamol concentration.
A Modification of the Trinder AutoAnalyzer Method for Glucose
Authors: Richardson T.
Published: February 2014

This paper describes the application of the sulphonated 2,4-dichlorophenol/glucose oxidase method of Barham and Trinder for the estimation of blood glucose to the AutoAnalyzer I and AutoAnalyzer II. Use has been made of the increased sensitivity achieved with this reagent to (1) increase sampling rates, with concomitant reduction in sample volume, (2) reduce the consumption of enzymes required, and (3) reduce carryover, all without significant loss of precision.
One Year's Experience with a Regional Hormone Assay Service
Authors: Challand G. S. , Kitchin E. G. , McCallum Mary , Moore C. J.
Published: February 2014

To provide a service in England and Wales for specialised assays, clinical chemists envisaged a multi-tier system with area, regional, and supraregional laboratories. The Department of Clinical Biochemistry at Addenbrooke's Hospital was established as a regional centre for hormone assays and formal operation started in June 1975. The assays which seemed most suitable for regional development in East Anglia were those for investigating the pituitary-gonad and pituitary-thyroid axes. Most of these were introduced in the first year of operation. A specialised laboratory was not set up: instead, endocrine assays were integrated into a large service laboratory and little expenditure was needed for specialised facilities or staff. The work load of endocrine assays increased markedly during the first year of operation, but the main source of requests was local rather than regional. This lack of use by a region has implications for all three tiers of the specialised service. It suggests that effective centralisation of specialised assays is impracticable unless a dictatorial approach to the problem of rationalisation is made at regional and area level.
Assessment of the Beckman System 1
Authors: Potezny N. , Quelch J. , Fuller B. , Geary T. D.
Published: February 2014

The System 1 produced results for glucose and urea which were precise and accurate. It proved suitable as a general laboratory instrument as it samples 28 μl of specimen, is able to calibrate itself, produces results in three minutes, and has the capacity to analyse 56 samples an hour.
Diagnostic Value of Urine Mercury Measurements
Authors: Taylor Andrew , Marks Vincent
Published: February 2014

A review of referrals to a regional heavy metals centre for possible mercury poisoning was made. Samples were received either from subjects who were well but were known to have some contact with mercury or from patients with an illness under investigation but undiagnosed. The problems associated with diagnosis of mercury toxicity in the absence of known exposure are illustrated by two case reports.
Data Processing in Pathology Laboratories: The Phoenix System
Authors: Abson J. , Prall A. , Wootton I. D. P.
Published: February 2014

This paper completes the description of the Phoenix system by outlining the additional programs necessary to maintain the data files in a satisfactory condition and prevent them from becoming overfilled. The standards of training required by the operating staff are discussed and an assessment is made of the system performance in terms of cost/benefit. This was achieved by observing the time spent by staff during a period when the throughput of work was accurately measured. From these figures it is possible to estimate the needs of another laboratory. Finally, the continued extension of the computer facilities into other pathology disciplines and the provision of terminals in the hospital is described.
15α-Hydroxyoestriol and other Polar Oestrogens in Pregnancy Monitoring
Authors: Taylor N. F. , Shackleton C. H. L.
Published: February 2014

Although oestriol measurements are well established for the assessment of ‘at risk’ pregnancies, there are a number of other oestrogens, excreted during pregnancy, which contain additional hydroxyl groups and might be more sensitive indicators of the condition of mother or fetus. Some of these result from the action of hydroxylases possibly present only in the fetus and others from maternal hydroxylations. We review the evidence for the biosynthesis of these polar oestrogens, summarise methods of measurement, and compare values obtained in normal and pathological pregnancies. There is as yet insufficient evidence to enable their potential value to be confirmed.
Comparison of Three Automated Methods of Serum Triglyceride Analysis
Authors: Postle A. D. , Goodland F. C.
Published: February 2014

Two new automated methods for serum triglyceride analysis are described and compared with each other and with an established chemical method. They are a chemical method requiring no glycerol blank correction and a commercially available fully enzymatic method requiring no prior lipid extraction. Both methods had higher quality control precision and faster sampling rates than the established method. Comparison of duplicate analyses of a random series of serum samples by all three methods gave a closer correlation between the new methods than between either and the conventional method.
The Origin of the Acidosis in Hyperlactataemia
Authors: Zilva Joan F.
Published: February 2014

Anaerobic glycolysis produces lactate, ATP, and water but there is no net change in the number of hydrogen ions: it does not produce lactic acid. The acidosis usually associated with hyperlactataemia is caused by hydrolysis of the ATP, with release of hydrogen ions. By contrast, ATP turnover by aerobic mechanisms is not acidifying because the released hydrogen ion is re-utilised as more ATP is formed. Gluconeogenesis from lactate does not utilise hydrogen ions directly—in fact, it produces them. The associated net H+ utilisation is caused by the aerobic generation of the ATP and GTP required to drive glycolysis in reverse. It is suggested that only by understanding these important biochemical facts can the clinician found his diagnosis and treatment on a firm, rational basis.
Enzyme Induction by Drugs
Authors: Marshall William J.
Published: February 2014

Summary The properties of the hepatic microsomal, drug detoxicating, enzyme system are reviewed with particular reference to its inducibility. Induction is modified by various factors of which the diet is particularly important. A theoretical model system for induction has been proposed and this is discussed. There are a number of methods for assessing microsomal enzyme induction in man, none of which is ideal. Nevertheless, induction is a well recognised phenomenon in man and has a bearing on the metabolism of a number of endogenous substances. The effect of induction on steroid metabolism and the relationship between inducers, vitamin D, and metabolic bone disease is discussed. Bilirubin metabolism is affected by changes in microsomal enzyme activity and inducers have been used therapeutically in some cases of hyperbilirubinaemia. The relationship between drugs and the hepatic porphyrias is reviewed. The hepatic microsomal enzyme system is but one of many inducible enzymes and the role of induction in general in metabolic regulation is emphasised.
Quantitative Estimation of Clinically Important Monosaccharides in Plasma by Rapid Thin Layer Chromatography
Authors: Menzies I. S. , Mount J. N. , Wheeler M. J.
Published: February 2014

Summary A method is described for the quantitative estimation of clinically important monosaccharides in plasma or whole blood by direct densitometry of chromatographically-separated zones on silica gel layers. Simple modifications of technique originally introduced to improve the reproducibility of paper chromatography have now been adapted for thin layers. The present method is based on peak height measurement with an internal marker correction. Galactose, fructose, D-xylose, and 3-O-methyl glucose can be estimated in addition to glucose, either singly or in combination, within three or four hours, using an initial sample volume of 0·5 ml. With reasonable experience and skill a coefficient of variation of 3 to 6 %, depending on sugar concentration, can be achieved without replication, and the limit of sensitivity is about 0·05 mmol/l. When the performance was compared with an automated glucose oxidase/peroxidase system for glucose and the recovery for the other monosaccharides was calculated, the results were satisfactory.
Origin of an Elevated Plasma Alkaline Phosphatase Activity in Non-Jaundiced Patients
Authors: Cleeve H. J. W.
Published: February 2014

Summary Samples from 260 non-jaundiced patients with elevated plasma alkaline phosphatase activities were analysed for γ-glutamyltransferase and 5′-nucleotidase activity, and for alkaline phosphatase isoenzyme pattern. The plasma γ-glutamyltransferase activity was found to be a more sensitive index than that of plasma 5′-nucleotidase in confirming the presence of a liver component of the elevated plasma alkaline phosphatase. If the γ-glutamyltransferase level is normal it is probable that the increase in plasma alkaline phosphatase activity is of bone origin. However, an elevated γ-glutamyltransferase result does not exclude a bone component; in this situation plasma alkaline phosphatase isoenzymes should be estimated. The causes of elevated activities of plasma alkaline phosphatase, 5′-nucleotidase and γ-glutamyltransferase, found in this investigation were generally the same as those found by other workers. The effect of treatment by drugs on γ-glutamyltransferase, an inducible enzyme, needs more investigation.
Noradrenaline to Adrenaline Ratio in Amniotic Fluid as an Index of Fetal Maturity
Authors: Woodman D. D. , Watson D. , Hatch U.
Published: February 2014

Summary Amniotic fluid lecithin to sphingomyelin ratio (L/S) and adrenaline concentration, noradrenaline concentration, and noradrenaline to adrenaline ratio (NA/A) were measured in 50 normal women late in pregnancy. Between gestation weeks 37 and 43 the maturity-linked increase in L/S ratio was accompanied by similar increases in NA/A ratio and noradrenaline but by decreases in adrenaline concentration. Although the amniotic fluid NA/A ratio reflects fetal sympathetic nervous system development rather than pulmonary development as mirrored by the L/S ratio, a high correlation existed between log NA/A and L/S, indicating that the NA/A ratio could provide a further index of fetal maturity.
Anomalous Behaviour of Control Sera in Automated Versions of the Kind and King Alkaline Phosphatase Method
Authors: Longlands M. G. , Wiener K.
Published: February 2014

Summary Differences in alkaline phosphatase activity of some commercial control sera were observed when comparing manual with AutoAnalyzer versions of the Kind and King procedure. This phenomenon was found to be associated with sera boosted with exogenous alkaline phosphatase and to be owing mainly to inadequate provision of buffer in some automated methods. It is suggested that a modification to the SMA procedure may lessen the problem, but the constraints of the system necessitate a compromise. There was better precision after the modification had been introduced. Awareness of this phenomenon is of paramount importance if commercial sera are to be used in any way in the calibration of automated systems for alkaline phosphatase assay.
An Optimised Radioimmunoassay for mAternal Serum α1-Fetoprotein using Polyethylene Glycol
Authors: Khadempour M. H. , Laing I. , Gowenlock A. H.
Published: February 2014

Summary A radioimmunoassay for α1-fetoprotein in human maternal serum at 15–20 weeks' gestation using polyethylene glycol to separate bound and free antigen is described. A number of variables has been investigated to define optimal conditions for use at this gestation. The method gives results which agree with those from a double-antibody technique. It has good precision in the critical concentration range, and recoveries are satisfactory. The importance of including sufficient serum protein in the analytical system is stressed.

There were systematic differences between three standard preparations of α1-fetoprotein, but three out of four antisera tested gave very similar results. The implications for screening for neural tube defects in early pregnancy are discussed.
Measurement of Plasma Renin Activity as a Valid Estimation of Plasma Angiotensin Status
Authors: Roulston J. E. , Macgregor G. A. , Adam Theresa , Markandu Nirmala D.
Published: February 2014

Measurement of plasma renin activity is widely used as an indirect assessment of plasma angiotensin II concentration. There has been some controversy over the validity of this assay as an estimate of circulating angiotensin II levels because, during the in vitro generation of angiotensin I by renin, over a period of time, substrate concentration may diminish to such an extent that it becomes rate-limiting, giving an artificially low reflection of angiotensin II levels. In this paper the initial angiotensin I concentration, that is the concentration before in vitro angiotensin I generation, has been compared with the corresponding plasma renin activity for 2752 individual plasma samples. A linear relationship was found between the initial angiotensin I concentration and the plasma renin activity below 60 ng ml−1 h−1. This indicates that, under the conditions of this assay, substrate does not appear to become rate-limiting except at exceedingly high levels of plasma renin activity. These results appear to provide further validation for the use of plasma renin activity measurement as a reflection of the concentration of circulating angiotensin II levels.
Urinary Excretion of Lysozyme and N-Acetyl-β-D-Glucosaminidase in the Diagnosis of Renal Allograft Rejection
Authors: Ellis L. , McSwiney R. R. , Tucker Susan M.
Published: February 2014

The urinary excretion of N-acetyl-β-D-glucosaminidase (NAG) has been claimed to be of high diagnostic value in indicating acute renal graft rejection. Similar claims have been made for the significance of urinary lysozyme excretion. Serial measurements of urinary lysozyme and NAG have been made in 35 patients after renal transplantation, and during 52 suspected rejection episodes. A close correlation has been found between these two parameters although they did not consistently change in parallel. The use of both assays may give a better indication of impending rejection than either assay alone.
Comparison of Three Kits for the Enzymatic Determination of Urea
Authors: Fraser C. G. , Fudge A. N.
Published: February 2014

A comparative evaluation of Beckman (A), Boehringer (B), and Calbiochem (C) kits for the enzymatic end-point determination of urea has been carried out. Acceptable within-day and day-to-day precision was obtained with all kits. The recoveries obtained fulfilled the criteria of Logan ( CRC Critical Reviews in Clinical Laboratory Sciences, 1972, 3, 271–289). Correlation between the results obtained by all kit methods and the diacetyl monoxime continuous-flow method, the reference method in this study, was excellent, but all methods evidenced a net negative bias at urea levels up to at least 20 mmol/l. We recommend kit A as the most satisfactory for routine use, consider kit B to be in the main acceptable, and suggest that kit C has disadvantages regarding both the accuracy attainable with quality control materials and the lack of information on blank correction for interfering compounds.
Drift Correction—A Comparative Evaluation of Some Alternatives
Authors: McLelland A. S. , Fleck A.
Published: February 2014

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.
Caeruloplasmin: A Plasma Protein, Enzyme, and Antioxidant
Authors: Gutteridge J. M. C.
Published: February 2014

Multifunctional roles of the plasma protein, caeruloplasmin, have been briefly reviewed under three main headings. These are protein functions, enzymic activity, and antioxidant protection. As a plasma protein it is said to play a role in the transport of copper. Since some 95 % of serum copper is associated with caeruloplasmin, measurement of the protein provides a useful guide to copper levels. Enzymic functions are related to its oxidase activity. Substrates commonly used for laboratory assay include non-biologically occurring aromatic amines and polyphenols. More recently, a physiological function has been proposed in which the enzyme oxidases iron from the ferrous to ferric state for binding to apotransferrin. This enzymic function of caeruloplasmin has been designated ‘ferroxidase’. In vitro studies have shown that caeruloplasmin can inhibit the peroxidation of polyunsaturated fatty-acids. This function is in part related to its ferroxidase activity. No antioxidant activity has yet been demonstrated in vivo but this possibility is speculatively discussed.
Some Laboratory Correlates of Drinking Habits
Authors: Whitfield J. B. , Hensley W. J. , Bryden D. , Gallagher H.
Published: February 2014

The effect of drinking habits on the frequency distributions of eight biochemical or haematological test results was studied in 7915 patients attending a multiphasic health testing centre.

Increasing incidences of abnormal results with increasing alcohol intake, at levels of alcohol intake habitual for a large proportion of the population, were found for plasma gamma-glutamyl transpeptidase, triglycerides and uric acid, and for erythrocyte mean corpuscular volume. Of four frequently used liver function tests, aspartate aminotransferase, alkaline phosphatase, bilirubin, and albumin, only aspartate aminotransferase was strongly affected by drinking habits.

These findings have relevance for the detection of individuals whose drinking habits are harmful to them, and for the interpretation of ‘profile’ results.
Detection and Incidence of B and C Vitamin Deficiency in Alcohol-Related Illness
Authors: Baines M.
Published: February 2014

The activity of the red blood cell enzymes transketolase, glutathione reductase, and aspartate transaminase, and their activation by the coenzymes thiamine, riboflavin, and pyridoxine, the pyruvate tolerance test, the leucocyte vitamin C concentration, and the activity in serum of γ-glutamyl transferase were measured in a series of 35 patients with alcohol-related illness. The incidence of thiamine deficiency was 31 % as assessed by the activation of transketolase, and 55 % as assessed by the pyruvate tolerance test. The incidence of riboflavin deficiency was 23 % and of ascorbic acid deficiency 91 %. No cases of pyridoxine deficiency were detected.

The pyruvate tolerance test was found to be a more sensitive test of thiamine deficiency than the transketolase activation, and the activation of red blood cell aspartate transaminase was found to be a poor indicator of pyridoxine deficiency. There was a poor correlation of the γ-glutamyl transferase activity with the degree of vitamin deficiency, suggesting that alcohol exposure is only partly responsible for the observed vitamin deficiency.
Plasma 25-Hydroxyvitamin D and Alkaline Phosphatase Isoenzymes in Hyperthyroidism
Authors: Cleeve H. J. W. , Brown I. R. F.
Published: February 2014

Plasma 25-hydroxyvitamin D (25-OHD) values in 22 hyperthyroid patients did not differ significantly from those of controls matched for age, sex, and the time of year that plasma samples were taken. In the hyperthyroid group, plasma alkaline phosphatase was significantly higher than in controls, and an increase in bone type alkaline phosphatase occurred in 50 %. In the 18 female hyperthyroid patients the plasma γ-glutamyl transferase was significantly increased compared with controls. Mean values for plasma albumin, alanine transferase, and calcium showed no significant difference between hyperthyroid and control patients.
Validation of the Self-Displacement Technique for Estimation of Specific Radioactivity of Radioimmunoassay Tracers
Authors: Roulston J. E.
Published: February 2014

There has been controversy recently about the validity of the data-analysis of the self-displacement technique for estimation of specific radioactivity. This paper investigates the technique theoretically and provides practical corroboration of the results.
Inappropriate Methods for the Emergency Determination of Plasma Paracetamol
Authors: Stewart M. J. , Adriaenssens P. I. , Jarvie D. R. , Prescott L. F.
Published: February 2014

Methods for the estimation of plasma paracetamol which depend on acid hydrolysis to p-aminophenol without a prior extraction step also measure inactive metabolites which are present in high concentrations.

The extent of the overestimate obtained with such methods was determined using 24 samples from patients after paracetamol overdosage. There was a positive error of between 40 and 700 % compared with a high-performance liquid chromatographic reference method which measured only unchanged paracetamol.

These non-specific methods should not be used to determine the need for specific therapy in patients with paracetamol poisoning.
Laboratory Assessment of Prolactin Status
Authors: Cowden Elizabeth A. , Ratcliffe Wendy A. , Beastall G. H. , Ratcliffe J. G.
Published: February 2014

The laboratory assessment of prolactin status was evaluated by detailed study of 921 subjects (587 normal subjects and 334 patients with pathological conditions). The effect on serum prolactin levels of age, sex, circadian rhythm, pulsatility of secretion, stress, drug ingestion, and pregnancy was defined in normal subjects. The normal prolactin responses to stimulation (TRH, metoclopramide) and suppression (L-dopa, bromocriptine) were also determined. Basal prolactin levels were measured in patients with defined pathological conditions including prolactinoma, idiopathic hyperprolactinaemia, acromegaly, Cushing's disease, chronic renal failure, primary hypothyroidism, pituitary ablation, Kallman's syndrome, Nelson's syndrome, growth hormone deficiency, gonadotrophin deficiency, craniopharyngioma, panhypopituitarism, and chronic progressive arthropathy. Based on these data, a strategy for the routine laboratory assessment of prolactin status is outlined.
Detection of Alcoholic Cardiomyopathy by Serum Enzyme and Isoenzyme Determination
Authors: Fink R. , Marjot D. H. , Rosalki S. B.
Published: February 2014

Serum creatine kinase and lactate dehydrogenase isoenzymes were studied in 73 patients with alcoholism, including two patients with clinical alcoholic cardiomyopathy and 28 patients with haemodynamic evidence (systolic time interval abnormality) of disordered myocardial function. No isoenzyme abnormalities suggestive of myocardial injury were observed. We conclude that isoenzyme examination is unsuitable for the early detection of myocardial damage from alcohol.
Enzyme Immunoassay: A Review
Authors: O'sullivan M. J. , Bridges J. W. , Marks V.
Published: February 2014

In the last few years, the use of enzyme labels in immunoassays has been investigated. The aim of this review is to evaluate critically the role of such labels in clinical biochemistry. Special attention has been given to the problems involved in preparing enzyme labels and the ways in which such labels can be used in a variety of heterogeneous and homogeneous assay systems.
Paracetamol: A Report of a Regional Quality Control Scheme
Authors: Epton J.
Published: February 2014

The results from an external quality control scheme for the assay of paracetamol in serum are reported. A preferential method of assay has not become evident, but, as a result of the scheme, some laboratories have changed or modified their techniques or have re-established the limits of detection.

The majority of laboratories were able to estimate paracetamol satisfactorily at those levels which are of clinical importance. The overall group performance has shown little change.

The programme has had considerable impact in so far as it has led to a mutually useful interchange of information and trouble shooting.
Changes in Serum Creatine Kinase Isoenzyme Activities after Surgical Procedures and Cardioversion
Authors: Lamplugh Sheila Marguerite , Johnson P. , Turner W. L. , Deegan T.
Published: February 2014

Serum activities of creatine kinase (CK) and its isoenzymes were monitored before and 16 to 20 hours after a variety of surgical procedures and cardioversion. Changes in total CK and CK MM activities in the surgical patients were consistent with the extent of trauma; changes in these activities in the cardioversion patients were more variable, ranging from —2 to 1829 U/l, and were unrelated to the applied electrical force. CK MB activity was unchanged after cystoscopy but rose moderately in 60 % of patients after cholecystectomy, in 43 % of patients requiring only implantation of a new pacemaker box, and in 87 % of patients after implantation of an entire pacemaker system. No increase exceeded 6U/l. Fifty per cent of patients requiring cardioversion showed rises; the maximum value was 40·9 U/l.
Accuracy and Linearity of Spectrophotometers in Clinical Chemistry Laboratories
Authors: Stevens John F
Published: February 2014

Solutions of cobalt nitrate sealed in vials were circulated to all clinical chemistry laboratories in the United Kingdom. Participants reported wavelengths of maximum absorbance together with the actual absorbances obtained. The results were compared with values obtained from the National Physical Laboratory.

The results show a wide scatter, and several instruments were extensively repaired or replaced as a result of the survey. The most recently marketed machines had the best performance, and it is suggested that regular quality control and maintenance of the machines is vital. It is intended to set up a scheme for regular monitoring of spectrophotometer performance.
Serum Gamma-Glutamyl Transferase and a Somatic Health Score in Middle-Aged Men
Authors: Trell E , Petersson B , Kristenson H , Fex G , Larme P , Yettra M , Hood B
Published: February 2014

In an ongoing population investigation of middle-aged men in Malmö, Sweden, several health screening variables showed strong but crude individual covariations with the level of the hepatic enzyme, serum gamma-glutamyl transferase (GGT). These variables were combined, according to an analysis of their normal distributions, into a score index which exhibited a much smoother correlation with low, normal, and elevated levels of GGT when tested in a random population subsample. It is concluded that this scoring system may find further utilisation as a general descriptive method of recording statistical covariations between health screening tests and sum them up.