bluuebunny/crossref_metadata_2025 huggingface dataset:
The Analysis of Urinary Meta- and Para-Tyramine by Gas Chromatography with Electron-Capture Detection
Authors: Walker P L , Sandler M
Published: February 2014

A simple, reliable method for the analysis of urinary meta- and para-tyramine has been developed. Sample purification was achieved by a weak anion-exchange column, followed by extraction into ethyl acetate at pH 10·2. The heptafluorobutyryl derivative was measured by packed column gas chromatography with electron-capture detection, using para-hydroxyphenylpropylamine as internal standard. The results agreed well with those obtained by gas chromatography-mass spectrometry. The daily output of unconjugated and conjugated meta- and para-tyramine by 23 adults was measured. In consecutive 24 h urine samples from a single subject there was little day-to-day variation in the level of excretion of unconjugated meta- and para-tyramine, whereas the conjugated amines exhibited marked fluctuations.
Analysis of Proteinuria Using a Commercial System for Automated Electrophoresis and Isoelectric Focusing
Authors: Jackson P J , Sampson C J , Cooper E H , Heney D , Brocklebank J T
Published: February 2014

We describe an investigation of proteinuria using Pharmacia PhastSystem™ electrophoresis apparatus. The analysis of urinary proteins by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) of unconcentrated urine followed by silver staining took about 2 h and could clearly demonstrate tubular dysfunction or glomerular damage in urines with a negative or only trace-positive dip-stick test for protein. In addition, we show the identification of urinary proteins by immunoblotting from SDS-PAGE gels and the characterisation of Bence-Jones proteins by isoelectric focusing (IEF) and immunoblotting.
Post-Convulsive Lactic Acidosis in Diabetic Patients
Authors: Krentz A J
Published: February 2014

Diabetic patients have an increased risk of developing epileptic convulsions compared with the non-diabetic population. Generalised seizures may cause a severe, but self-correcting, lactic acidosis for which specific treatment is both unnecessary and potentially hazardous. Two cases of post-convulsive lactic acidosis occurring in diabetic patients are reported. The cause of the acidosis was confirmed only in retrospect in each case.
Factors Influencing the Free Androgen Index in a Group of Subfertile Women with Normal Ovaries
Authors: Eden J A , Carter G D , Jones J , Alaghband-Zadeh J , Pawson M
Published: February 2014

Eighty-five regularly cycling women with normal ovaries at laparoscopy, were studied to determine the factors that influence the free androgen index (FAI). It was found that body mass index (BMI), age of the patient and the phase of the menstrual cycle that the blood was collected can all affect the FAI. It is recommended that where possible, specimens should be collected in the early follicular phase to avoid misinterpretation of the result.
Salivary and Plasma Free Testosterone and Androstenedione Levels in Women Using Oral Contraceptives Containing Desogestrel or Levonorgestrel
Authors: Swinkels L M J W , Meulenberg P M M , Ross H A , Benraad Th J
Published: February 2014

The effect of oral contraceptives (OC) containing a combination of ethinyloestradiol (EE2) and either desogestrel (Dg/EE2) or levonorgestrel (Lg/EE2) on plasma concentrations of sex hormone binding globulin (SHBG), total testosterone (T), free T, total androstenedione (A), free A and on salivary T and A concentrations have been studied. SHBG concentrations were higher in the Dg/EE2 group than in the Lg/EE2 group. Total T, measured by RIA with prior extraction and chromatography, is also higher in the Dg/EE2 group. Per cent free T was lower in the Dg/EE2 group. Plasma free T and free A concentrations were the same in both groups. However, free T and free A were significantly lower in the OC-groups than in controls.

In contrast, by direct assay, no difference in total T was observed between the OC-groups. Since the per cent free T was lower in the Dg/EE2 group, it would be concluded that free T in the Dg/EE2 group is lower than in the Lg/EE2 group.

Salivary free T and free A concentrations did not differ between control and OC-groups. There was good correlation between salivary and free hormone concentrations within each group. We conclude that the concentrations of androgens in saliva do not necessarily directly reflect their free concentrations in plasma.
Evaluation of an Immunoassay for Plasma Sex Hormone-Binding Globulin: Comparison with Steroid-Binding Assay under Physiological and Pathological Conditions
Authors: Cunningham S K , McKenna T J
Published: February 2014

It is possible that alterations in sex hormone-binding globulin (SHBG) binding capacity are due to changes in binding kinetics rather than changes in concentration and, therefore, the immunoreactivity of SHBG may not reflect the binding activity. In this study an immunoradiometric (IRMA) assay was evaluated and the results compared with those of an established binding capacity assay. The correlation between the results of the IRMA ( y) and binding assay ( x) for 179 specimens was r=0·984, y=0·95 x+5·9. Irrespective of the method used, SHBG values in normal non-pregnant women were significantly ( P<0·05) higher than those in normal men, hirsute women, women with polycystic ovary syndrome, hyperprolactinaemic women and obese women, and were significantly less than those in pregnant women; SHBG levels in hirsute women rose during treatment with certain anovulants and fell in genetic males during the second decade of life independent of androgen levels or activity. While being technically simpler SHBG-IRMA provides comparable results to the classical binding assay, indicating that immunoreactivity is an excellent index of binding activity.
The Use of an Intact Molecule Parathyroid Hormone Assay in Disorders of Calcium Metabolism
Authors: Bicknell E J , Van't Hoff W
Published: February 2014

We present the results obtained using a 1–84 human parathyroid hormone (PTH) assay in patients with abnormal calcium metabolism. A normal range was established in a series of healthy volunteers. Patients with surgically proven hyperparathyroidism (HPT) showed increased PTH levels which were separate from the normal range. Patients with probable hyperparathyroidism and milder hypercalcaemia showed a raised median PTH level but the range overlapped with normal. Patients with hypercalcaemia of malignancy showed reduced PTH levels and these patients were readily differentiated from those with probable and proven HPT by the use of the assay.

In patients with chronic renal failure PTH values ranged from normal to high, the PTH concentration was found to be correlated with plasma alkaline phosphatase, but not with plasma creatinine.
Body Composition and Plasma Creatine Kinase Activity
Authors: Swaminathan R , Ho C S , Donnan S P B
Published: February 2014

Plasma creatine kinase (CK) activity and lean body mass (LBM) (by anthropometry) were measured in 120 women (20–82 years) and 70 men (20–82 years). Plasma CK activity and LBM was higher in men than in women. In men plasma CK activity was significantly correlated (product moment correlation coefficient) with LBM and negatively with age. In women plasma CK activity was significantly correlated with age. Partial correlation coefficient calculation showed a significant correlation between plasma CK and LBM both in men and in women. We conclude that in healthy subjects the plasma CK activity is related to LBM, but the LBM is not a major determinant of plasma activity in healthy subjects.
Performance of Screening Tests for Porphyria
Authors: Deacon A C
Published: February 2014

The clinical utility of screening tests for porphyria has been assessed in 201 cases referred to Northwick Park Hospital. Routine screening in the referring laboratories was unreliable giving both false negative and positive results. Only 43% of porphyries were correctly identified, apparently due to poor analytical sensitivity. Evidence is presented to show that the adoption of alternative semiquantitative tests for porphyrins employing spectrophotometric scanning of acidified urine or of faecal extracts will overcome many of these problems.
Zinc Absorption in Haemodialysis Patients
Authors: Foote John W , Hinks Lesley J
Published: February 2014

The gastrointestinal absorption of zinc by haemodialysis patients has been investigated. Subnormal plasma zinc responses were observed in nine haemodialysis patients during oral zinc tolerance tests. These patients also had reduced leucocyte zinc concentrations which did not respond when 50 mg (0·77 mmol) of zinc was given daily by mouth for a period of 4 months. White cell zinc concentrations measured in another group of 10 haemodialysis patients were reduced initially, but rose to normal levels over 4 months when zinc was added to the fluid used for dialysis. These data suggest that the intestinal absorption of zinc was defective in the dialysis patients participating in this investigation.
A Computer Program for Rapid Generation of Receiver Operating Characteristic Curves and Likelihood Ratios in the Evaluation of Diagnostic Tests
Authors: Pellar Thomas G , Leung Fred Y , Henderson A Ralph
Published: February 2014

We describe a MUMPS program to facilitate the evaluation of the diagnostic effectiveness and efficiency of laboratory tests using receiver operating characteristic (ROC) curves and likelihood ratios (LR). Test results from a population with and without a disease are stored into retrievable, editable data bases. Either single or a combination (≤9) of different test data files can be accessed to generate tables of calculated frequency distribution, sensitivity, 1-specificity and LR at variable decision thresholds. The program also calculates the area under the ROC curve, confidence intervals and SE. The selection of the optimum cut-off value is assisted by graphical plots of frequency distribution, ROC and decision level curves as illustrated by using some ‘cardiac’ enzyme tests.
The Effect of Calibration on the between-Laboratory Variation of Serum Fructosamine
Authors: Hill R P
Published: February 2014

Human pooled serum from diabetic and non-diabetic subjects, and calibrators containing glycated protein or 1-deoxy-1-morpholinofructose (DMF) in a variety of matrices, were distributed to 10 laboratories. When they used their own assay conditions and calibrators, the inter-laboratory variation was unacceptably high. However, when the pool from diabetic patients was reassayed using a calibrator with an assigned value prepared from freeze-dried human serum, and containing no DMF, inter-laboratory variation was reduced significantly. Interlaboratory agreement for the pool from non-diabetic subjects remained poor despite recalibration. Recalibration using either serum or albumin based solutions of DMF as calibrator failed to effect any significant reductions in inter-laboratory variation. Secondary calibrators based on a protein matrix with no added DMF are recommended for routine use.
Oestradiol Assays: Applications and Guidelines for the Provision of a Clinical Biochemistry Service
Authors: Ratcliffe W A , Carter G D , Dowsett M , Hillier S G , Middle J G , Reed M J
Published: February 2014

This paper reports on the provision of a clinical biochemistry service for serum oestradiol. The pathophysiology and recognised applications of oestradiol assays are discussed and the current availability of assay reagents and methodologies reviewed. Data are presented on the analytical performance of assays for serum oestradiol in the UK External Quality Assessment Scheme (UKEQAS) and general guidance is offered to laboratories providing a diagnostic service for this analyte.
A Simple Improved Method for the Measurement of Cyclosporin by Liquid-Liquid Extraction of Whole Blood and Isocratic HPLC
Authors: Fletcher Stephen J , Bacchus Robby A
Published: February 2014

The current HPLC methods of cyclosporin measurement have been reviewed and all aspects assessed.

A simple isocratic C-18 reverse phase HPLC method with improved efficiency is described for the routine measurement of cyclosporin in whole blood. An alkaline ether extraction is followed by an acid wash, solvent evaporation and two hexane washes of the reconstituted extract. The turn-round time for a single sample is 1 h. Daily batches of up to 40 patient samples can be easily measured with this method. The results are compared with those from the Sandoz radioimmunoassay (RIA) method.
Development and Evaluation of an Enzyme Inhibition Assay for Methotrexate
Authors: Kelly Michael G
Published: February 2014

A method for the measurement of methotrexate based on its inhibition of dihydrofolate reductase (EC 1.5.1.3) is described. The performance of the method is evaluated and a brief assessment of its clinical usefulness made.

Reaction time, pH, and the relative concentration of enzyme and inhibitor all have a significant effect on the shape of the standard curve. Pre-incubation of enzyme with methotrexate resulted in increased inhibition, but did not improve the sensitivity or linearity of the assay. Data are presented on the imprecision, specificity and accuracy of the method. The method is simple to perform, rapid and inexpensive.

The sensitivity and specificity of the method are such as to allow for effective monitoring of patients on methotrexate therapy.
Detection of Antibodies to the Human Immunodeficiency Virus by a Rapid Fluorescence-Labelled Immunosorbent Assay
Authors: Rocks Bernard F , Bertram Vanessa M R , Bailey M Philip , Riley Clifford , Thom Barry T
Published: February 2014

The development and assessment of a fluorescence-labelled immunosorbent assay for the detection of antibodies to the human immunodeficiency virus is described.

Test serum is incubated in microtitre wells on which antigens have been coated. If present in the test serum, antibodies to the human immunodeficiency virus bind to the solid-phase antigens. In turn the antibodies are quantified with anti-human immunoglobulin labelled with fluorescein. Positive samples produce an intense fluorescence which is measured in a spectrofluorimeter.

When used to test a panel consisting of normal serum and antibody-positive serum from infected patients the assay proved to be 100% specific and to have a sensitivity of 100%.

The assay has many of the advantages of micro enzyme-linked immunosorbent assays, but does not suffer from the drawbacks associated with the use of an enzyme label. It requires fewer manipulations and is quicker to carry out than an equivalent enzyme-linked test.
Multicentre Study of a New Test for TSH-Screening in Blood Spots
Authors: Brombacher P J , Henkel E , Kessler A C , Van Dieijen-Visser M P
Published: February 2014

A multicentre study for the detection of congenital hypothyroidism by enzyme-immunoassay of thyrotropin in filter paper blood spots is described. The method is accurate, with good precision and adequate sensitivity. No interference due to common blood constituents has been observed. Moreover, the TSH determination can easily be performed by photometric measurement of enzyme activity. Large series of samples can be processed by automation using common laboratory analysers. Values show good agreement with those obtained by RIA methods.
Why the Assay of Serum Cystine by Protein Precipitation and Chromatography Should Be Abandoned
Authors: Cooper J D H , Turnell D C , Green B , Wright D J , Coombes E J
Published: February 2014

The higher bias of serum cystine estimations by a HPLC method compared with those by ion exchange techniques is shown to be largely due to differences in the sample preparation procedures of the two techniques. The ion exchange methods utilised sulphosalicylic acid serum protein precipitation and post-column ninhydrin derivatisation of cystine, whilst the high pressure liquid chromatography technique employed automated dialysis for removal of proteins and pre-column ortho-phthalaldehyde derivatisation of cystine after its conversion to cysteine and then to S-carboxymethylcysteine. Examination of these procedures showed that whilst the high pressure liquid chromatographic method accurately estimates total serum cystine and cysteine, many factors affect the precision and accuracy of serum cystine estimations using the ion exchange techniques. In particular, serum protein precipitation techniques that are currently employed for the preparation of samples for cystine analysis by ion exchange chromatography should be abandoned.
A Study of the Hypouricaemic Effect of Tiaprofenic Acid
Authors: Lyfar Vivienne , Fernandes L , Thornton Elizabeth , Cook J G H
Published: February 2014

Tiaprofenic acid is a non-steroidal anti-inflammatory drug which also has hypouriceamic effect.

Studies involving 10 healthy volunteers were designed to investigate the mode of this effect.

We postulate that the site of action of tiaprofenic acid is at the cell membrane, the mechanism being an interference with the transport of uric acid from intra- to extra-cellular fluid thus limiting its passage into the plasma. The same mechanism acting on renal tubular cells impedes reabsorption thereby increasing uric acid clearance.
The Role of the Laboratory in the Investigation of Infertility
Authors: Butt W R , Blunt Susan M
Published: February 2014

The incidence and the causes of the various types of infertility in men and women are described. Accurate diagnosis of the cause or causes of a couple's infertility is important as the treatment is often expensive and lengthy. A thorough clinical investigation of the couple will indicate which laboratory tests to embark upon. Endocrine abnormalities may account for about a third of diagnoses in women but are rare in men. Standard immunoassay procedures are used for hormone assays to diagnose endocrinopathies and should be performed in a logical sequence. They help to identify hyperprolactinaemia and to distinguish primary gonadal failure from lesions of the hypothalamic-pituitary axis. The common drugs available for treatment are listed and guidelines are given on management during treatment. Hormone assays are useful, but ultrasonic scanning is efficient and rapid and is becoming the preferred method for monitoring follicular growth.
Long-Term Performance of the Fructosamine Assay
Authors: Dominiczak M H , Macrury S M , Orrell J M , Paterson K R
Published: February 2014

We have investigated the long-term performance of the fructosamine assay based on secondary glycated protein standards and attempted to define the interpretation of varying degrees of increase in fructosamine concentration in comparison to haemoglobin A1 (HbA1) values both in insulin dependent (IDDM) and non-insulin dependent (NIDDM) diabetic patients. Between-batch imprecision of fructosamine over 5 months was (CV) 2·5% at 2·09 mmol/L, 2·8% at 3·52 mmol/L and 3·6% at 4·14 mmol/L. Variation of fructosamine concentration in vivo in stable diabetic patients monitored over 8–18 weeks was 2·3% to 7·1%. Fructosamine correlated with HbA1 both in IDDM ( n = 110, r = 0·701, P < 0·001) and NIDDM ( n = 71, r = 0·764, P < 0·001). Specificity and sensitivity of fructosamine for the prediction of degree of control assessed on the basis of HbA1 level (cut-off point for good vs. poor control, HbA1 = 10%) was determined. In NIDDM, specificity above 90% was achieved at a fructosamine concentration of 3·4 mmol/L with a corresponding sensitivity of 64·1%. 22·5% of patients were classified differently on the basis of fructosamine as compared to HbA1. In IDDM, specificity over 90% was achieved at 3·8% mmol/L fructosamine with a sensitivity of 35%. Discordancy rate between HbA1 and fructosamine based assessment of control was 31·8%.

The assessment of diabetic control based on fructosamine may be different from that based on HbA1, particularly in IDDM. Fructosamine and HbA1 should be used as complementary rather than alternative tests.
Clinical and Laboratory Evaluation of a Two-Site Immunoradiometric Assay for Intact Parathyroid Hormone
Authors: Newman D J , Ashby J P
Published: February 2014

The analytical performance and clinical utility of a direct immunoradiometric assay (IRMA) for intact 1–84 human parathyroid hormone (PTH) was evaluated. The assay is available commercially (Allégro intact PTH, Nichols Institute) and utilises two affinity purified region-specific antisera against either 1–34 (radiolabelled antibody) or 39–84 (solid phase antibody) human PTH. High assay sensitivity (detection limit, 1·4 pg 1·84 PTH/mL) permitted the measurement of PTH in all normocalcaemic individuals studied. Elevated results were obtained in all patients (21 studied) with histologically proven primary hyperparathyroidism (PHPT) and 34 out of 35 patients with presumptive PHPT. Thirteen out of 24 patients with non-parathyroid hypercalcaemia had suppressed results, but the remainder had concentrations within the reference range.
A Non-Extraction HPLC Method for the Simultaneous Determination of Serum Paracetamol and Salicylate
Authors: Dawson C M , Wang T W M , Rainbow S J , Tickner T R
Published: February 2014

A direct injection HPLC method for the sumultaneous measurement of serum paracetamol and salicylate is described using a Pinkerton internal surface reversed-phase column with benzoic acid as internal standard. The method is linear to at least 1000 mg/L for both drugs and shows good precision at levels of 62–500 mg/L. None of the drugs tested for interference affected the quantitation of either drug. In patient samples, the values obtained with this method correlated well with those from enzymatic paracetamol and Trinder salicylate methods.
Some Effects on Light Scattering Intensity and Red Blood Cell Size Distribution Histograms Due to Sphering
Authors: Bartels P C , Helleman P W , Roijers A F M , Soons J B J
Published: February 2014

At present most haematology blood cell analysers routinely provide red blood cell (RBC) size distribution histograms. Sophisticated improvements of the instruments have re-awakened interest in the study of size histograms. The quantitative information derived from the histograms may be applied more fruitfully if insight is available, with respect to some essential principles of sizing technology and methods for treatment of RBCs before measurement. In this study the consequences of sphering RBCs are investigated in relation to the generation of size distribution histograms by means of methods based on light scattering intensity (LSI). Sphering of RBCs results in considerably narrower histograms than unsphered RBCs. The overall signal to noise ratio increases and there is a broader gap between large platelets and microcytic RBCs. Narrower size distribution ranges will enable closer modes to be separated. Compared to unsphered RBCs, microcytic sphered RBCs yield increased LSI whereas macrocytic sphered RBCs yield decreased LSI.
Evaluation of Red Blood Cell Size Distribution Histograms: The Fraction of Microcytes
Authors: Bartels P C , Helleman P W , Soons J B J
Published: February 2014

A method is described for the assessment of the fraction of microcytes from the red blood cell (RBC) size distribution histogram. For quantification of the fraction of microcytes an upper threshold corresponding with a RBC volume of 70 fL is established. The reference interval for the fraction of microcytes covers a range from 0·01 to 0·09.

In order to examine the relationship between the fraction of microcytes and the mean cell volume (MCV) values computer simulation studies were performed. The computer simulations are based on a Gaussian distributed reference RBC histogram as generated on a Technicon H 6000/H 601 Hematology Analyser. From our studies it is shown that determination of the fraction of microcytes yields a higher sensitivity than MCV values for detecting small populations of microcytes. In particular, measurement of the fraction of microcytes is very sensitive to minor changes in the MCV values if a normocytic RBC population combined with a microcytic RBC fraction shows a wide dispersion in their cell volumes.
The Evaluation of Erythrocyte Thiamin Diphosphate as an Indicator of Thiamin Status in Man, and its Comparison with Erythrocyte Transketolase Activity Measurements
Authors: Baines M , Davies G
Published: February 2014

HPLC measurement of the major physiological form of thiamin, thiamin diphosphate, in erythrocytes (ETDP) has been assessed as an indicator of thiamin status and compared with erythrocyte transketolase activity (ETKA) before and after activation with exogenous thiamin diphosphate (TDP effect). The comparison was made by following the response of the parameters to incubation of erythrocytes with thiamin and by measurements in alcoholic, elderly and student groups.

All parameters were responsive to the thiamin content of their environment, but ETDP was at least as sensitive as TDP effect and more sensitive than ETKA in reflecting thiamin uptake and utilisation by erythrocytes. There was a better correlation between ETDP and ETKA than between ETDP and TDP effect. All the groups showed a significant positive correlation between ETDP and ETKA, but only the elderly and the alcoholic groups showed a significant negative correlation between ETDP and TDP effect. The lack of correlation between ETDP and TDP effect in the student group may be due to the relative imprecision of TDP effect measurements at the lower end of the reference range.

ETDP is more stable than ETKA in frozen erythrocytes, is easier to standardise and is not affected by various factors which can influence the enzyme assay. Measurement of ETDP is, therefore, recommended for first line assessment of thiamin status.
Analytical Goals for Quantities Used to Assess Thyrometabolic Status
Authors: Browning Margaret C K
Published: February 2014

Analytical goals for imprecision derived from data on intra-individual variation for total T4, free T4, total T3, free T3 and thyrotropin (TSH) are coefficients of variation (CV) ⩽ 2·5, 4·7, 5·2, 3·9 and 8·1%, respectively. If total T4 is used to monitor replacement therapy with thyroxine, a more stringent goal of CV ⩽ 1·;4% is appropriate. For those analytes for which biological variation data are not available, analytical goals may be derived either from reference intervals or from the ‘state of the art’ as judged from the performance of a stated proportion of laboratories participating in an interlaboratory quality assessment scheme. Analytical goals for imprecision for reverse T3 and thyroxine-binding globulin derived from reference values are CV ⩽ 10·;7 and 7·;2%, respectively. The goal for inaccuracy is that there should be none. Statements regarding the detection limit of an assay should be replaced with information about the range of concentrations over which specified goals for imprecision are met. If goals are not achieved at concentrations which are used for clinical decision making the 95% confidence limits of the extreme values of the ‘working range’ should be calculated using the relevant imprecision. Improved analytical performance will result in better between-laboratory comparability and eventually allow the use of universally applicable reference values.
Duplicates or Singletons?—An Analysis of the Need for Replication in Immunoassay and a Computer Program to Calculate the Distribution of Outliers, Error Rate and the Precision Profile from Assay Duplicates
Authors: Raggatt P R
Published: February 2014

The nature, frequency, statistics and methods of detection of both Gaussian and catastrophic errors in immunoassay are described. The method of sequential analysis is applied to the rates of catastrophic errors and is used to calculate the number of results which must be examined in order to achieve a stated confidence that the error rate is acceptable so that a rational decision on use of duplicate or singleton assay can be made. A simple computer program is described, which allows computation of the precision profile and an analysis of errors using accumulated data from duplicate assays. These methods have been applied to an enzyme amplification immunometric assay for thyroid-stimulating hormone (TSH) and an analysis is made of the errors detected in a sample of 1419 patient results.
Serum Protein Changes after Abdominal Surgery
Authors: Shakespeare Peter G , Ball Andrew J , Spurr Errol D
Published: February 2014

Changes in the concentrations of 11 serum proteins following surgery for a variety of conditions have been investigated. Protein changes were analogous to those observed after injury or trauma, but showed differences in the detailed behaviour of the pattern of change. Marked increases in the concentrations of five acute-phase reactant proteins (APRP) were seen, with maximum concentrations usually being reached 2 days after surgery in patients who made an uncomplicated recovery from their operations. Considerable differences were observed between the patterns of change of APRP in patients who developed complications during recovery and in patients who made an uncomplicated recovery from surgery. Concentrations of C-reactive protein and alpha-1 antichymotrypsin (ACT) were much higher in the patients who developed complications, with ACT concentrations providing the clearest separation between the groups. The main factor influencing the changes in APRP during the recovery period appeared to be the development of sepsis. Preoperative concentrations of APRP had no prognostic value for identifying patients at risk of developing complications. The study suggests that the localisation of inflamed tissue involved in the disease processes may influence the detailed behaviour of the acute-phase reactant proteins.
Glycated Fibrinogen: A New Index of Short-Term Diabetic Control
Authors: Hammer M R , John P N , Flynn M D , Bellingham A J , Leslie R D G
Published: February 2014

Fibrinogen is a plasma protein with a short half-life of four days and, therefore, glycated fibrinogen may be valuable as an index of short-term diabetic control. We have developed a simple, rapid method for determining glycated fibrinogen using affinity chromatography. The differences in the percentage of glycated fibrinogen between normal subjects, well-controlled diabetics and poorly-controlled diabetics were highly significant. There was a significant correlation between glycated fibrinogen and glycated haemoglobin for all these subjects. However, in selected subjects with rapidly improving diabetic control the difference between the fall over three days in glycated fibrinogen and glycated haemoglobin was highly significant. In subjects with deteriorating control over an average of four weeks there was a significant difference between the increase in glycated fibrinogen and glycated haemoglobin. We suggest that glycated fibrinogen may be a valuable adjunct to glucose measurements in the assessment of short-term diabetic control due to its rapid change following alterations in control.
Serum Fructosamine in Uraemia, Myeloma and Acute Inflammatory Disorders—Relationship to Serum Glucose and Albumin Levels
Authors: McCance D R , Clarke K C , Kennedy L
Published: February 2014

There has been considerable interest in the serum fructosamine assay as a measure of glycated serum proteins. We have measured serum fructosamine in three groups of patients—those with uraemia; those with multiple myeloma; and those with acute inflammatory conditions—none of whom were known to have diabetes. Serum fructosamine was significantly higher in the uraemic group than in the other two, and also than in a control group. When allowance was made for prevailing serum albumin levels fructosamine was shown to be increased in the acute inflammatory group also. There was a significant correlation between random plasma glucose and serum fructosamine only when fructosamine was adjusted for prevailing albumin levels.

In control and uraemic subjects there was a significant positive correlation between serum fructosamine and albumin levels, whereas in the myeloma group there was a negative correlation with serum protein.

These data would suggest the need to take into account serum albumin levels and protein composition if serum fructosamine is accurately to reflect short-term integrated glycaemia.
Serum Immunoreactive Trypsin in Tropical Pancreatic Diabetes Syndrome
Authors: Yajnik C S , Katrak A , Kanitkar S V , Naik S S , D'Souza V , Dandona P
Published: February 2014

Fifteen patients with tropical pancreatic diabetes syndrome (TPDS), 16 insulin-dependent diabetics (IDD), 27 non-insulin-dependent diabetics (NIDD) and 14 normal subjects, all from India, were investigated for markers of β-cell (C-peptide) and exocrine (immunoreactive trypsin; IRT) reserve. IRT and C-peptide concentrations were the lowest in TPDS, lower than normal in IDD, and not significantly different from normal in NIDDs. There was a highly significant correlation ( rs = 0·;D93; P < 0·;00001) between IRT and C-peptide (measured in 50% of patients and controls) concentrations when all diabetic groups were combined. Such a correlation was absent when TPDS patients were considered in isolation, largely because of the markedly low IRT concentration. Fourteen of 15 patients (93%) with TPDS had subnormal IRT concentrations, of which 11 had IRT values of less than 50 μg/L. These IRT values are similar to those previously reported in cystic fibrosis. Only 6 of 16 IDDs (38%) had subnormal IRT concentrations, of which only one was below 50 μg/L. These data suggest that exocrine pancreatic reserve is markedly diminished in TPDS and that a subnormal IRT concentration may be a useful biochemical marker for this form of diabetes.
The Automated Enzymic Assay of D-Isocitrate in Human Urine
Authors: Pallanca J E , Denney R C , Rose G A
Published: February 2014

A simple, automated, enzymic assay for the analysis of D-isocitrate in urine is described. The method detects D-isocitrate in the range 0·;05–1·;00 mmol/L, producing within-batch and between-batch coefficients of variation of 1·;8–3·;2% and 2·;7–3·;0% respectively. The assay was also shown to be robust, tolerating extremes of sample pH. Of a wide range of substances tested, only Fe3+ ions interfered, but only at levels considerably in excess of those encountered in urine. D-isocitrate was stable in urine for up to one week at room temperature or at 4°C, with or without preservatives.
The Effect of Supplementation with Selenium and Vitamin E in Psoriasis
Authors: Fairris G M , Lloyd Barbara , Hinks Lesley , Perkins Pauline J , Clayton Barbara E
Published: February 2014

Since reduced concentrations of selenium in whole blood, plasma and white cells had previously been observed in psoriasis, 69 patients were supplemented daily with either 600 μg of selenium-enriched yeast, 600 μg of selenium-enriched yeast plus 600 IU of vitamin E or a placebo for 12 weeks. Before supplementation, the patients' mean concentrations of selenium in whole blood and plasma were reduced compared with those of matched healthy controls but their red cell glutathione peroxidase (GSH-Px) activity was normal. After 12 weeks supplementation the patients' mean whole blood, plasma and platelet selenium concentrations, platelet GSH-Px activity and plasma vitamin E concentration had risen significantly from the baseline values but their mean skin selenium concentration and red cell GSH-Px activity remained unchanged. The mean white cell selenium concentration rose only in the group receiving selenium alone. Neither supplementation regimen reduced the severity of psoriasis or produced side-effects.

The increase in platelet GSH-Px activity suggests that the supplements were bioavailable and that the patients' selenium status may have been reduced prior to supplementation. The failure of the selenium content of the skin to increase may explain why the patients' psoriasis remained unchanged during supplementation.
Assessment of the Potency of Different Standards in the Immunoradiometric Assay of ACTH
Authors: Dobson S H , Gibson S , White A
Published: February 2014

There is no generally accepted human international reference preparation for ACTH. The different centres offering clinical ACTH measurement therefore select assay standards from the limited range of human-purified and synthetic preparations currently available. We have examined the relative potencies of three synthetic ACTH standards in comparison with the NIBSC human-purified 1–39 (code 74/555) in a two-site immunoradiometric assay (IRMA) for ACTH. All of the standards produced parallel curves in the IRMA but there was a wide variation in potency between the preparations giving highly significant differences in quality control and patients' ACTH results. Standards supplied by the National Hormone and Pituitary Programme, Bachem UK Ltd and Universal Biologicals Ltd gave lower ACTH results than results calculated using the NIBSC preparation. The potency differences between these standards emphasise the need for a reference preparation and, in the meantime, the necessity to define normal reference ranges for each laboratory.
Increased Levels of Vaccenic Acid in Bronchogenic Carcinoma Tissue
Authors: Lawson Nigel , Husband David , McGuigan James , Watson Deirdre C T , Collins Francis J , Pandov Harry I
Published: February 2014

Employing capillary gas liquid chromatography the levels of palmitic, palmitoleic, stearic, oleic, cis-vaccenic, linoleic, arachidonic and docosahexaenoic acids were measured in lung tissue and lung tumours from 28 patients undergoing surgery for bronchogenic carcinoma. There were significant increases in the majority of fatty acids in tumour tissue compared to normal tissue when the results were expressed in absolute units. However, when the relative changes in fatty acid concentration were studied, the most consistent findings were a significant rise in vaccenic acid and a fall in palmitic acid in tumour tissue compared to normal tissue. This change in the vaccenic: palmitic acid ratio may reflect specific changes in fatty acid metabolism in bronchogenic carcinoma tissue involving a Δ-9 desaturase.
A Systematic Evaluation of Bathophenanthroline, Ferrozine and Ferene in an ICSH-Based Method for the Measurement of Serum Iron
Authors: Derman D P , Green A , Bothwell T H , Graham B , McNamara L , MacPhail A P , Baynes R D
Published: February 2014

The chromogenic substrates ferrozine and ferene were compared to bathophenanthroline disulphonic acid for the measurement of iron concentrations in aqueous and serum samples in an assay based on that of the Iron Panel of the International Committee for Standardisation in Haematology. Ferrozine and ferene were more sensitive than bathophenanthroline. Copper at physiological concentrations in plasma caused only minimal positive interference with all three chromogenic substrates when thioglycollic acid was used as the reducing agent, but when ascorbic acid was used significant positive interference occurred with ferrozine and ferene. Interference due to contaminating haem was comparable with all agents. Bilirubin and carotene produced no interference. Profound reductions in colour development were noted with EDTA plasma.
An Immunoprecipitation Assay for High Molecular Weight Alkaline Phosphatase in Human Serum
Authors: Maguire Gerald A , Adnan Halima
Published: February 2014

The serum of patients with obstructive liver disease may contain a high molecular weight form of alkaline phosphatase (high Mr alkaline phosphatase). The presence of this form of alkaline phosphatase is associated with hepatic malignancies. We have investigated the use of anti-alkaline phosphatase monoclonal antibodies which do not bind high Mr alkaline phosphatase in assays for high Mr alkaline phosphatase. Direct immunoprecipitation of liver and bone alkaline phosphatase with solid phase anti-liver alkaline phosphatase antibody (which also reacts with bone alkaline phosphatase) and measurement of the residual supernatant alkaline phosphatase activity led to a precise assay. Intestinal alkaline phosphatase interfered in this assay which, consequently, was of little use in the differential diagnosis of liver disease. Indirect precipitation of liver, bone, placental and intestinal alkaline phosphatase by soluble anti-liver alkaline phosphatase (which reacts with liver and bone alkaline phosphatases), soluble anti-intestinal alkaline phosphatase (which reacts with placental and intestinal alkaline phosphatases) and solid phase anti-mouse IgG led to an assay which, although less precise, showed more promise of being useful clinically.
Cytosolic Protein-Tyrosine Kinase Activities in Various Rat Tissues
Authors: Kobayashi Tomoko , Nakamura Shun-Ichi , Yamamura Hirohei
Published: February 2014

Suitable assay conditions for the detection of cytosolic protein-tyrosine kinase activities in crude extracts of various rat tissues have been determined. Cytosolic protein-tyrosine kinases showed common characteristics including substrate specificity and divalent cation requirement. Using (Val5) angiotensin II and Mn2+ rather than a src-related synthetic peptide, E11G1, and Mg2+, we obtained higher activities of cytosolic protein-tyrosine kinases. Among various rat tissues tested, spleen, bone marrow, thymus, small intestine, appendix and lung, in decreasing order of total activity, contained high activities of cytosolic protein-tyrosine kinases. These results suggest that the enzyme activities in lymphatic organs and in organs closely related to cell proliferation are high. The assay system described allows the precise measurement of cytosolic protein-tyrosine kinase activity in various rat tissues, both normal and malignant.
Identification of Glucagon-Like Peptide-1(7–36) Amide in Rat Brain
Authors: Yoshimoto S , Hirota M , Ohboshi C , Shima K
Published: February 2014

Acid-urea extract of rat brain was examined by glucagon-like peptide-1 (GLP-1) specific radioimmunoassay. A single peak was observed which co-eluted with GLP-1(7–36)amide on gel filtration and anion exchange chromatography. In contrast, GLP-1(1–37) was not detected under our experimental conditions. The fact that GLP-1 (7–36)amide, but not GLP-1(1–37), was present in rat brain suggests that preproglucagon was processed in the brain in the same manner as in the intestine and not as in the pancreas.
The Influence of Blood Sample Preparation on Measured Levels of Morphine and its Major Metabolites
Authors: Hoskin P J , Alsayed-Omar O , Hanks G W , Johnston A , Turner P
Published: February 2014

The effect of six different methods of blood sample preparation on concentrations of morphine (M), morphine-3-glucuronide (M3G) and morphine-6–glucuronide (M6G) have been investigated using a specific high performance liquid chromatography assay. No difference between glass or plastic tubes was seen in concentrations of M, M3G, or M6G; and no difference between plasma and serum in M and M6G concentrations. M3G concentrations, however, were significantly lower in plasma compared with serum. Heparin had no effect on M, M6G or M3G, whereas citrate in a glass tube produced consistently lower concentrations of M, M3G and M6G. Standardization of sample collection using plasma samples in plastic heparin tubes is recommended for future studies.
Comparison of Microscale Ultracentrifugation and Equilibrium Dialysis for the Determination of the Unbound Fraction of Theophylline in Human Serum
Authors: McKenzie K , Watson I D , Stewart M J
Published: February 2014

A microscale ultracentrifugation procedure for the measurement of free theophylline in serum is described and evaluated by comparison with an equilibrium dialysis method. Provided an ultracentrifuge is available, micro-ultracentrifugation is a simple, cost-effective technique for the routine determination of free drug fractions.
18-Hydroxycorticosterone as a Marker for Primary Hyperaldosteronism
Authors: Lapworth Ruth , Short Frances , James V H T
Published: February 2014

An assay for the measurement of 18-hydroxycorticosterone (18-OHB) in plasma has been validated. The method involves extraction of plasma with dichloro-methane, thin layer chromatography and radioimmunoassay with an iodinated 18-hydroxycorticosterone-3-carboxymethyloxime ligand. The plasma concentration of 18-OHB was measured in 16 patients with primary hyperaldosteronism and 20 control subjects. After overnight recumbency a significantly higher mean concentration of 18-OHB was found in the samples taken from the patients than in those from the control subjects. The degree of elevation did not clearly discriminate between patients with a unilateral adenoma and those with bilateral adrenal hyperplasia. A significant anomalous postural decrease in the 18-OHB concentration occurred in 10 of the 13 patients with an adenoma, whereas there was a significant postural increase in the three patients with hyperplasia.
A Simple Time-Resolved Fluoroimmunoassay of Total Thyroxine in Serum
Authors: Papanastasiou-Diamandis Anastasia , Bhayana Vipin , Diamandis Eleftherios P
Published: February 2014

We describe a non-isotopic heterogeneous competitive immunoassay of total thyroxine in serum. Thyroxine, released from its binding proteins by merthiolate (thimerosal), competes with immobilised thyroxine (thyroxine-bovine globulin conjugate) for binding to a monoclonal biotinylated antibody. The amount of biotinylated antibody bound, which is inversely related to the amount of thyroxine in the sample, is then quantified by adding streptavidin labelled with the europium chelator 4,7-bis(chlorosulphophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BCPDA) in the presence of excess Eu3+. The complex formed (bovine globulin-thyroxine-antibody-biotin-streptavidin-BCPDA-Eu3+) is measured on the solid-phase by time-resolved fluorescence. The assay is simple to perform and its characteristics are similar to those of other currently used immunoassay techniques.
Radioiodination for Therapy
Authors: Adam Theresa
Published: February 2014

A method for the radioiodination of antibodies for therapy is described. The method resulted in a high efficiency of labelling (88–94%) with negligible damage to the antibody. Good localisation of labelled antibody was demonstrated. Doses of radiation to operators were very low.
Serum Protein Electrophoresis: Italian Survey 1986
Authors: Aguzzi F , Petrini C , Gasparro C
Published: February 2014

In 1986 the Protein Commission of the Italian Society of Clinical Biochemistry (SIBIOC) carried out its second survey on the use of serum protein electrophoresis in Italian laboratories. Three serum samples plus a questionnaire were sent to the 253 laboratories which agreed to take part. The three samples had the following characteristics: Serum 1: a 60 g/L IgM-lambda monoclonal component (MC); Serum 2: an artificially split alpha-2 zone; Serum 3: a very faint lambda chain MC. These features were chosen to assess (a) the type of report; (b) the resolution quality of the electrophoretic technique; and (c) the laboratory capacity to detect a small MC.

The most significant features revealed by the survey were: (a) the poor capacity of assessment of the small MC in Serum 3 (only detected by 23·1% of laboratories); (b) the discouraging tendency to delegate electrophoretic diagnostic interpretation to ward physicians (44·4% of participating laboratories provided only densitometric values and graphs).
Diagnostic Value of Serum Testosterone Measurement in Infancy: Two Case Reports
Authors: Ismail A A A , Walker P L , Macfaul R , Gindal B
Published: February 2014

The diagnostic value of serum testosterone measurement and hCG stimulation during early infancy is highlighted by describing two unrelated cases in whom such investigations aided diagnosis and management. When performed on infants between 2 and 9 weeks of age, these measurements can provide valuable information on the integrity of the hypothalamic-pituitary axis in male infants and can identify the presence of testicular tissues in babies with abnormal or ambiguous genitalia.