bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Reliable Semiautomated Method for the Determination of Total Thiamine in Whole Blood by the Thiochrome Method with High-Performance Liquid Chromatography
Authors: Schrijver Jaap , Speek Andries J , Klosse Jan A , Van Rijn Herman J M , Schreurs Wil H P 
Published: February 2014

A sensitive and reliable method for the determination of total thiamine (vitamin B1) in whole blood has been developed which is suited for routine analysis. After extraction, and enzymatic hydrolysis of thiamine phosphate esters, thiamine is separated from interfering compounds by a fully automated high-performance liquid chromatographic (HPLC) system. Thiamine is detected fluorometrically as thiochrome. By calculating the concentration of thiamine on-line with the aid of a computer, it is possible to complete one analysis within four hours. Routine thiamine determinations can be carried out in a series of 120 samples within 48 hours. The within-assay and between-assay coefficients of variation of the analysis of total thiamine in whole blood were 4·2 and 4·4%, respectively. The between-assay analytical recovery of thiamine diphosphate added to blood samples was 99·9 ± 11·7% (mean ± SD). The HPLC method described has been applied also to the analysis of thiamine in plasma and erythrocytes. In agreement with other reports, it was found that about 80% of total thiamine of whole blood is present in the erythrocytes. Reference values of thiamine in whole blood of the human were found in the range 95–155 nmol/l.
Emergency Biochemistry Services—Are They Abused?
Authors: Smith A D Stuart , Shenkin Alan , Dryburgh Frances J , Morgan H Gemmel 
Published: February 2014

An out-of-hours emergency biochemistry service, which allows access by all medical practitioners of varying experience within a hospital, can lead to overuse or even abuse of limited and costly facilities. When the workload increases, problems of staffing a voluntary (but paid) working rota may emerge. An industrial dispute involving medical laboratory scientific officers (MLSOs) caused the role of the emergency service to be examined and alternative regulating mechanisms to be tested. Experience at Glasgow Royal Infirmary between 1974 and 1981 has been reviewed. From 1977 to 1979, when clinicians (usually junior) arranged analyses directly with the MLSOs, test numbers increased by about 26% per annum. This was not associated with any concomitant increase in the range of analyses offered. During a five-week period in 1980, consultant clinicians had to contact a consultant clinical biochemist to arrange all emergency analyses, and test numbers were reduced to 13% of the previous levels. Subsequently, all requests for emergency analyses were made by clinicians to laboratory medical staff, and test numbers fell to approximately 60% of 1979 levels. This requesting system is now firmly established. Continued vigilance is required to maintain the reduced level of requesting, but too great a limitation on emergency requests may cause less efficient patient management. Senior clinical staff should be encouraged to take greater responsibility for the use of emergency laboratory services.
Temperatures Used in the Determination of Enzyme Activity in Clinical Biochemistry Laboratories in Britain: Results of a Survey
Authors: Fleck A , Colley C M ,   Association of Clinical Biochemists
Published: February 2014

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°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°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° to determine enzyme activity. About one-third of laboratories consider it impracticable to change to 30°C, and of those replying to the question on whether they were willing to change to 30°C, 49% indicated that they were not willing to do so.
Serum Iron and Total Iron-Binding Capacity Determination by Flow-Injection Analysis with Atomic Absorption Detection
Authors: Rocks Bernard F , Sherwood Roy A , Turner Zoe J , Riley Clifford 
Published: February 2014

The deproteinised sample (150 μl) is ‘injected’ into a continuously flowing stream of deionised water which is pumped, via a capillary tube, to the nebuliser of an atomic absorption spectrophotometer. Analytical readout is obtained, in the form of transient peaks, 6 s after sample injection. Before injection traces of haemoglobin are removed from the serum by treatment with trichloroacetic acid-ascorbate solution. This protein precipitant facilitates rapid removal of haemoglobin bound iron without the need for heating. After centrifugation the supernatant solution is introduced into the flowing stream by use of a novel inexpensive ‘injector’. Analytical recovery and precision are good, and results compare well with those obtained by a standard AutoAnalyzer procedure.
Haematological and Biochemical Parameters in an Industrial Workforce
Authors: Gidlow David A , Church John F , Clayton Barbara E 
Published: February 2014

Biochemical and haematological data for two consecutive years are presented on about 2000 people from the workforce of a large chemical company. The data are examined for the influence of sex, age, season, time of blood sampling, and patterns of work on the various indices. In addition to the results confirming previously published work relating to the effects of age and sex, they provide interesting new information on the possible influences of seasons and patterns of work, that is, whether the subjects were shift or day workers. Further studies on the influence of these various factors are required, and our on-going survey will perhaps provide more definite data in due course. The findings show the importance of quantifying these variables, particularly in an industrial workforce where minor changes may be of significance.
Thyroxine and Thyroxine-Binding Globulin: Discriminant Formulae for the Separation of the Diagnostic Classes of Thyroid Function
Authors: Noe Dennis A 
Published: February 2014

The biochemical classification of thyroid functional status is often accomplished by the use of the thyroxine to thyroxine-binding globulin (T4:TBG) ratio. It has recently been shown, however, that the reference range of the T4:TBG ratio varies with the concentration of TBG. This makes the T4:TBG ratio an unwieldy diagnostic index. A more accurate and economical way to define thyroid function using T4 and TBG measurements is by linear discriminant formulae. This is so because T4 varies linearly with TBG at the T4 reference limits over a wide range of TBG concentrations. Using the T4 reference ranges established by Attwood and Atkin ( Ann Clin Biochem 1982; 19: 101–3), the following formulae are obtained: T4 (nmol/l)—4·05 TBG (mg/l)>94·5 indicates hyperthyroidism; T4 (nmol/l)—2·72 TBG (mg/l)<23·8 identifies hypothyroidism.
The Relationship between Liver Function Tests and Alcohol Intake in Patients Admitted to an Alcoholism Unit
Authors: Evans J R , Ogston S , Guthrie Anne , Johnston B , McKechnie L 
Published: February 2014

Values of various blood plasma tests have been determined in heavy drinkers admitted to an Alcoholism Unit and in a reference group of occasional social drinkers. These tests were total protein, albumin, bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), asparate amino transferase (AST) and amylase. The aim of this study was to assess the reliability and validity of GGT and AST as indices of alcohol intake in heavy drinkers entering an Alcoholism Unit. The data indicate that in the patients group intra-personal variance and analytical variances are relatively small compared with the between-person variance. The data also indicate, however, that in the patients group GGT and AST are not valid group indices of alcohol intake since the between-person variation is large and the correlation with alcohol intake is weak due to large differences in the dose-response relationship between individuals. AST and GGT are poor indicators of alcohol intake in admissions to an Alcoholism Unit.
Performance of Three Enzymic Methods for Filter Paper Glucose Determination
Authors: Burrin J M , Price C P 
Published: February 2014

Collection of blood spots on filter paper offers a practical alternative for home monitoring of diabetic patients. We have compared the merits of three protein precipitants, trichloracetic acid (TCA), perchloric acid (PCA) and sulphosalicylic acid (SSA) for the elution of glucose from the filter paper, and their subsequent effects on three enzymic methods, glucose dehydrogenase (GDH), hexokinase (HK), and glucose oxidase (GOD) for the determination of glucose using a microcentrifugal analyser. The combination of TCA elutant with the GDH method was superior with respect to time course of reaction and elution time from the filter paper, and was chosen for routine use. Within- and between-batch precision for this method was 2·7% and 3·2% respectively at normal glucose concentrations. Recovery of glucose added to whole blood was 110 ± 5%. Comparison with an automated glucose oxidase method for plasma glucose gave a slope of 1·1, intercept of −0·7 and a correlation coefficient of 0·9 ( n = 64). We conclude that the combination of TCA and glucose dehydrogenase provides a robust, precise and accurate method for the quantitation of glucose in filter-paper blood spots. The procedure offers increased sensitivity and better precision than GOD methods. The use of TCA as elutant gives a faster elution time and has the least effect on any of the enzymic methods.
External Quality Assessment of Quantitative Urinary Analysis
Authors: Legg E F , Hurrell A E 
Published: February 2014

An external quality-assessment scheme was initiated among a group of 13 clinical chemistry laboratories for the urinary analysis of calcium, chloride, creatinine, glucose, osmolality, phosphate, potassium, protein, sodium, urate and urea and also for the estimation of creatinine clearance. The greatest inter-laboratory imprecision occurred in the assay of urinary protein. The results of the survey are compared with similar schemes elsewhere and their significance discussed.
The Evaluation of Imprecision in Collaborative Immunoassay Quality-Assessment Programmes
Authors: Compton P , Cole Benedicte , Stuart Margaret , Egan G 
Published: February 2014

The calculation of within-laboratory imprecision in quality-assessment (QA) programmes normally involves combining data from different analyte concentrations to calculate an average standard deviation (SD) or coefficient of variation. However, for immunoassay neither of these parameters is concentration independent. This paper describes a method of calculating within-laboratory imprecision in QA programmes by assuming a linear relationship between SD and analyte concentration. This method is used in programmes conducted by the Australian Joint Working Party for Quality Control in Immunoassay to calculate imprecision at the limits of the reference range. Results from these programmes show that this method better represents the differences in imprecision between analytes, methods and laboratories than the calculation of a single imprecision parameter. The method is trivial for a computer and its robustness has been validated by Monte Carlo simulation. It is suggested that major differences in laboratory performance between different QA programmes may be due to inappropriate calculation of single imprecision parameters.
Biochemical and Haematological Response to Alcohol Intake
Authors: Shaper A G , Pocock S J , Ashby D , Walker M , Whitehead T P 
Published: February 2014

In a clinical survey of 7735 middle-aged men, alcohol consumption has been related to 25 biochemical and haematological measurements obtained from a single blood sample. Most measurements showed some association with alcohol consumption, gamma-glutamyl transferase (GGT) being the most strongly associated. Lead, mean corpuscular haemoglobin (MCH), mean corpuscular volume, high-density lipoprotein-cholesterol (HDL-C), urate and aspartate transaminase also showed substantial associations with alcohol intake. Using a discriminant analysis technique, a simple score based on five variables (GGT, HDL-C, urate, MCH and lead) provided the best discrimination between heavy drinkers (e.g. more than three pints of beer daily) and occasional drinkers, but still failed to identify more than half of the heavy drinkers. This combined score may prove a useful measure of an individual's biochemical/haematological response to alcohol consumption for use in epidemiological and clinical studies of alcohol-related disorders. The use of such indices should complement but not replace measures of alcohol intake derived from questionnaires.
Glucose Tolerance Test and Glycosylated Haemoglobin Measurement for Diagnosis of Diabetes Mellitus—An Assessment of the Criteria of the WHO Expert Committee on Diabetes Mellitus 1980
Authors: Albutt Eileen C , Nattrass M , Northam B E 
Published: February 2014

Fasting glycosylated haemoglobin was analysed in 535 consecutive patients having an oral 75 g glucose tolerance test for diagnostic purposes. A reference range for fasting glycosylated haemoglobin was established from patients with a non-diabetic glucose tolerance test as defined by the World Health Organisation Expert Committee on Diabetes Mellitus. The predictive value of a glycosylated haemoglobin of over 100% (mean normal + 3 SD) for detecting a diabetic glucose tolerance test was 89% but sensitivity was only 43%. A raised glycosylated haemoglobin is useful for confirming the diagnosis of diabetes mellitus in patients with long-standing hyperglycaemia but glycosylated haemoglobin is within the reference range in many patients with newly developed diabetes or other minor abnormalities of glucose tolerance. The glucose tolerance test must remain the test of choice in these patients.
Lack of Comparability between CEA Analyses Using Three Different Methods
Authors: Davidson Helen , Pledger D R , Belfield A 
Published: February 2014

Three different methods for the assay of carcinoembryonic antigen were investigated—radioimmunoassay, enzyme-linked immunoassay, and a commercial immunoradiometric assay. Two standard preparations of CEA were used: the 1st British Standard (73/601) and a commercial preparation obtained as a component of the IRMA kit. Serum samples were assayed by each method against each standard material. Significant differences between results were obtained when the different methods were compared. When using the two standards in the same assay system no significant differences were found between results. A possible explanation and the implications of these findings for the routine assay of CEA are discussed.
The Diagnostic Value of Glycated Haemoglobin Levels in Post-Mortem Blood
Authors: Hindle Eric J , Rostron Glenise M , Gatt John A 
Published: February 2014

Glycated haemoglobin (HbA1) in post mortem blood was estimated following electrophoretic separation. HbA1 was measured in preserved and unpreserved specimens and its stability in vitro was studied. No significant change in the proportion of HbA1 was observed in samples stored for more than 40 days at 4°C. Specimens were analysed for glucose and HbA1. There was poor correlation between these parameters, and no significant difference between the mean values of HbA1 in specimens collected within 24, 48 and 72 or more hours following death, from subjects with no previous history of diabetes. The levels were within the laboratory reference range, whilst eight specimens collected from diabetic subjects demonstrated elevated levels. There was no significant difference in HbA1 levels collected from different sites in the body even though the glucose levels showed some variation. The measurement and apparent stability of HbA1 post mortem may be a more useful diagnostic test than glucose alone where diabetes may be suspected.
The Development of a Fluoroimmunoassay for β-2-Microglobulin in Serum
Authors: Playford R J , Dawnay Anne , Cattell W R , Landon J 
Published: February 2014

A liquid-phase fluoroimmunoassay has been developed for the measurement of β-2-microglobulin in undiluted serum or plasma. Protein labelled with fluorescein-isothiocyanate at a molar ratio of 1:2 respectively is employed as a tracer together with an antiserum to β-2-microglobulin raised in a sheep. Separation is achieved by means of rabbit anti-sheep immunoglobulin G and, following precipitation of the bound fraction by centrifugation, the free fraction together with any potentially interfering factors is removed in the supernatant. Finally the precipitate is dissolved and the fluorescence measured. The assay is simple and rapid in that all reactants, including the second antibody, can be added at the start of the assay and equilibrium is attained within 60 min. The assay is reproducible and sufficiently sensitive to allow measurement of normal serum levels and has a wide range avoiding the need for sample dilution. Results correlated well with those of an established radioimmunoassay.
A Steady-State Gel Filtration Method on Micro-Columns for the Measurement of Percentage Free Testosterone in Serum
Authors: Wheeler M J , Nanjee M N 
Published: February 2014

A method is described for measuring the percentage of free testosterone in serum using steady-state gel filtration on micro-columns of Sephadex G50 (fine). The method has a coefficient of variation of 4·0% and up to 20 samples can be processed in a day. Reference ranges have been established for normal women at different stages of their menstrual cycles and for normal men; there is good agreement with values published by workers using other methods. This method combined with a specific and precise method for measuring total testosterone opens up the possibility for the routine measurement of free testosterone concentration in serum.
A Direct Radioimmunoassay for the Determination of Adrenocorticotropic Hormone (ACTH) and a Clinical Evaluation
Authors: Marts C J , Koppeschaar H P F , Veeman W , Thijssen J H H 
Published: February 2014

A direct radioimmunoassay for the determination of ACTH in a small volume of serum was developed using a commercially available antiserum and tracer. A single-stage radioimmunoassay with an incubation period of 4 days gave reliable and reproducible ACTH values. In the incubation medium 0·1% 2-mercaptoethanol was used as the antioxidant. During a 15-month period the assay has been used routinely in the laboratory. The coefficient of variation was less than 10% in the physiological and pathological range. A normal range of 12 to 60 ng/L was found. The reliability of the assay is demonstrated by results obtained in patients with disorders of the pituitary-adrenal axis.
A Simple, Optimised and Rapid Assay for Urinary Free Catecholamines by HPLC with Electrochemical Detection
Authors: Davidson D F , Fitzpatrick J 
Published: February 2014

A rapid method is described for the determination of urinary free catecholamines by HPLC with electrochemical detection. Optimised and equilibrium assay conditions are assessed for sample preparation, separation and detection. Catecholamine stability is maintained during the assay procedure by the addition of a combined reducing agent. Variability in recovery between aqueous standards and urine samples is minimised by dilution of samples with a concentrated Tris buffer solution. Ethyl acetate washing of an acid eluate is performed after and not before an alumina adsorption step in order to make the procedure as simple and rapid as possible. The method is evaluated and has thus far identified two cases of phaeochromocytoma and one case of neuroblastoma.
Hormone Studies in a Case of Virilisation Due to Ovarian Tumour
Authors: Fleetwood J A , Watson M J , Wastell Hilary J , Weddell Ann 
Published: February 2014

The investigation is described of a 62-year-old female patient who presented with severe virilisation; her plasma testosterone concentration was grossly elevated at 37–9 nmol/L. Measurement of plasma androstenedione, dehydroepiandrosterone (DHEA) and DHEA-sulphate, urinary 17-oxosteroids and urinary ‘free’ Cortisol suggested an ovarian source of androgens. An ultrasound scan indicated the presence of an ovarian mass which was removed and classified as a Sertoli—Leydig cell tumour (arrhenoblastoma) combined with a mucinous cystadenoma. Following operation plasma testosterone levels returned to normal. The excessive pre-operative testosterone production appeared to have had little effect on the plasma level of SHBG, since levels remained similar before and after removal of the tumour. Serum LH and FSH levels were higher post-operatively.
Evaluation of the Diagnostic Value of Serum Bile Acid in the Detection and Functional Assessment of Liver Diseases
Authors: Cravetto C , Molino G , Biondi A M , Cavanna A , Avagnina P , Frediani S 
Published: February 2014

The diagnostic usefulness of fasting total serum bile acids (SBA/F) in the detection of liver diseases and assessment of different aspects of hepatic function alteration was evaluated in 61 healthy subjects and 186 patients with liver disease. The value of SBA/F was compared with other routine tests. In 49 healthy subjects and 92 patients, serum bile acids were also measured after the im administration of Ceruletide as a cholecystokinetic agent (SBA/C). The diagnostic efficacy for the detection of disease states was better with aspartate-aminotransferase (EC 2.6.1.1) and alanine-aminotransferase (EC 2.6.1.2) than with SBA/F. When SBA/C was also determined the diagnostic efficacy was not substantially better than the SBA/F test. In the assessment of hepatocellular necrosis SBA/F showed a higher rate of misclassification errors compared to alanine-aminotransferase (mean error 45% vs 17%), whereas SBA/F gave similar results with direct bilirubin and pseudocholinesterase (EC 3.1.1.8) in the evaluation of cholestasis (mean error 40% vs 41%) and impaired biosynthesis (mean error 39% vs 40%), respectively. Serum bile acid determination did not show any significant diagnostic advantage with respect to the other routine liver tests.
Evaluation of a Time-Resolved Immunofluorometric Assay for Serum Thyroid Stimulating Hormone
Authors: Paterson N , Biggart E M , Chapman R S , Beastall G H 
Published: February 2014

The LKB ‘Delfia™’ immunofluorometric assay for serum TSH has been evaluated. The assay is simple and rapid to perform and is capable of processing in excess of 100 specimens within a working day. The sensitivity of the assay is 0·05 mU/L, with a working range extending beyond 324 mU/L. The change in signal at each point over the standard curve approaches 1000-fold, significantly greater than that of a typical immunoradiometric assay. Mean figures for intra-assay and inter-assay precision were 4·7% and 8·6% CV, respectively. Mean recovery of added TSH was 98·3%, and samples containing high levels of endogenous TSH diluted parallel to the standard curve. The method showed good correlation with an immunoradiometric assay for TSH. The reference ranges for clinically defined groups of subjects were euthyroid 0·47–3·84 mU/L ( n = 83); primary hypothyroidism 15 — >324 mU/L ( n = 28); thyrotoxicosis <0·05 mU/L ( n = 46). It is concluded that the ‘Delfia’ assay offers the clinical biochemistry laboratory an attractive and reliable alternative to a sensitive immunoradiometric assay for serum TSH.