bluuebunny/crossref_metadata_2025 huggingface dataset:
An Adaptable Computer Interface for Radioimmunoassay
Authors: Nurse David R , James Timothy J
Published: February 2014

To assist data handling of results derived from radioimmunoassay the RIACalc Multigamma counter package was interfaced to a laboratory information system. The interface was bidirectional and allowed transfer of worklists and results. A suite of programs was written for the laboratory information system that enabled flexible data processing to meet a range of laboratory requirements. One utility within the suite contained a simple user definable rule based routine for automatically requesting additional tests. Use of the interface and new software improved laboratory efficiency and illustrated the potential benefits of decision making systems.
A Radioimmunoassay for Human Urinary Prealbumin
Authors: Beetham R , Dawnay A , Ghany C , Dubrey S , Miles J
Published: February 2014

We describe a validated radioimmunoassay for prealbumin in urine. Using timed overnight urine samples, the normal reference range was less than 10–148μg/L; or less than 1·8–9·6μg/mmol creatinine, excretion in women being significantly greater than in men ( P<0–05); or less than 7–3–114 ng/min with no significant difference in excretion rate between the sexes. Urines exhibited loss of immunoreactivity after storage at — 20°C and thawing. No such loss occurred after storage for 4 weeks at 4°C or room temperature. The urinary excretion of prealbumin was highly correlated with that of albumin ( r = 0·85), and clearance relative to creatinine was 2 × 10−6, the same order as that of albumin.
Early Diagnosis of Acute Myocardial Infarction: CK-MB and Myoglobin Compared
Authors: Kilpatrick W S , Wosornu D , McGuinness J B , Glen A C A
Published: February 2014

We have measured changes in plasma concentration of creatine kinase MB (CK-MB) and myoglobin in 50 patients admitted to the Coronary Care Unit with chest pain of presumed cardiac origin. Eight serial blood samples were obtained in the 6 h period following admission and both CK-MB and myoglobin concentrations were measured.

We compared the performance of single values of both tests. Myoglobin concentration, in the coronary care population studied, proved to be as specific as CK-MB concentration (92–6% in both cases) but with sensitivity of 100% being achieved 1 · 5 h post admission rather than 4 h post admission in the case of CK-MB.

On this evidence, measurement of plasma myoglobin could prove useful in the rapid diagnosis of myocardial infarction with consequent effects on optimal Coronary Care utilisation and selection of patients for thrombolytic therapy.
Role of Plasma Phosphate Measurements in Detecting Rickets of Prematurity and in Monitoring Treatment
Authors: Aiken C G A , Sherwood R A , Lenney W
Published: February 2014

Twice weekly plasma and urine measurements were made in 24 very low birth weight infants. Intravenous feeding was given whilst infants required respiratory support. Subsequently they received breast milk or formula milk with a vitamin D supplement of 400 U/day. Fourteen babies required intravenous feeding for more than 10 days. Six developed radiological rickets or severe osteoporosis, and these infants had plasma phosphate levels < 1 · 2 mmol/L on breast milk or < 1 · 8 mmol/L on formula milk. Babies without radiological rickets had plasma phosphate levels > 1 · 2 mmol/L on breast milk and > 1 · 8 mmol/L in all but one on formula milk. Successful treatment of rickets was associated with a rise in plasma phosphate to the above levels. Untimed urine calcium and phosphate concentrations expressed as creatinine ratios were not helpful in detecting babies with rickets, but may be useful in monitoring therapy.
Clinical Evaluation of Sodium Ion Selective Field Effect Transistors for Whole Blood Assay
Authors: Thompson John M , Smith Stephen C H , Cramb Robert , Hutton Peter
Published: February 2014

Sodium ion selective field effect transistors (ISFETs) were evaluated for their performance in measurement of sodium ions in whole blood for ‘near patient’ analysis in operating theatres and intensive care units. Performance was evaluated in comparison with a standard clinical laboratory sodium/potassium ion analyser (Radiometer KNA1) and with sodium and potassium assays using flame photometry on the plasma from each whole blood specimen. The imprecisions (coefficients of variation) of three ISFETs for sodium ion assay were 1·08, 1·56 and 1·10%, respectively. Robust bivariate linear regression (reweighted least squares preceded by least median of squares) of the ISFET versus KNA1 sodium ion activity yielded a regression coefficient of 1·08 and an intercept of −18·2 mM. The influence of potassium, protein and lipid on the measurement of sodium ions by both ISFETs and the KNA1 was assessed using robust multiple regression (also based on reweighted least squares preceded by least median of squares). In the regression versus flame photometry, protein was found to be more influential for the KNA1 (glass sodium ion selective electrode) than for the ISFET. Potassium had no influence on assays using the ISFET, but had a weak negative influence on assays using the KNA1. Two ISFETs lasted for more than 200 assays each demonstrating their robustness in the assay of whole blood.
In vitro Stability of Endogenous Parathyroid Hormone-Related Protein in Blood and Plasma
Authors: Hutchesson Andrew C J , Hughes Susan V , Bowden Sarah J , Ratcliffe Wendy A
Published: February 2014

We describe a systematic comparison of the effects of anticoagulants, protease inhibitors and conditions of sample handling on the in vitro stability of endogenous parathyroid hormone-related protein (PTHrP) in blood from patients with hypercalcaemia of malignancy (HM). When blood was separated within 15 min of collection, PTHrP1–86 levels measured by two-site immunoradiometric assay in serum and heparinized plasma were significantly lower than in ethylenediaminetetra-acetic acid (EDTA) plasma ( P<0·02). PTHrP was unstable in blood kept at 20°C for 4 h and inclusion of protease inhibitors reduced, but failed to abolish, this instability. In blood collected in the presence of EDTA, inclusion of leupeptin either alone or in combination with pepstatin and aprotinin increased the mean half-time of disappearance from 3·9 to 10·1 and 11·2h, respectively ( P<0·05). In contrast, when blood containing EDTA was separated within 15 min, PTHrP was stable in plasma at 20°C for at least 4 h. As a result of the instability of PTHrP1–86 immunoreactivity in whole blood at ambient temperatures we advise that for our immunoradiometric assay (IRMA) blood collected in EDTA should be separated within 15 min, and the plasma frozen until assay.
Interaction of 1,9-Dimethylmethylene Blue with Glycosaminoglycans
Authors: Stone Janet E , Akhtar Naseem , Botchway Stanley , Pennock Charles A
Published: February 2014

The specific binding of 1,9-dimethylmethylene blue (DMB) with glycosaminoglycans (GAGs) was studied including molecular analysis of the GAG species using mass spectrometry. The dye solution was unstable under any storage conditions. Inorganic analysis showed that the purity of the dye was variable from different sources. False negative results could be obtained when using impure dye. Binding of the dye with GAG resulted in the formation of a complex with an absorption maximum at 525 nm. The absorbance of the complex was linearly correlated with GAG concentration up to 150mg/L. The specific molar extinction coefficients of individual GAG molecules were calculated in relation to the molar absorbance of the GAG-dye complex and the carbon and nitrogen contents of the GAGs. The results indicated that binding of dye occurred at both the ionized sulphate and carboxyl groups on the GAG molecules. Improvements of the DMB-binding method for the measurement of GAGs are suggested.
External Quality Assessment of Techniques for the Detection of Drugs of Abuse in Urine
Authors: Wilson J F , Smith B L , Toseland P A , Williams J , Burnett D , Hirst A D , Watson I D , Horn A N
Published: February 2014

Five chromatographic and six immunoassay techniques were compared using data reported by 131 participants in the UK National External Quality Assessment Scheme for Drugs of Abuse in Urine. Twenty Five samples were studied containing none or one of three concentrations of amphetamine, barbiturates, benzodiazepines, benzoylecgonine, methadone and morphine. Technique sensitivity and specificity achieved with realistic clinical samples of 25 mL vol were assessed as the percentage of true positive and true negative tests, respectively. Thin-layer chromatography was inadequate for the detection of several analytes, the sensitivity for 0 · 5 mg/L of benzoylecgonine being < 30%, and for 1 · 5 mg/L of amphetamine < 86%. Gas chromatography with mass spectrometry was significantly less sensitive than other techniques for the detection of 0·5 mg/L of benzoylecgonine (71%) and 1 · 5 mg/L of morphine (88%). High-performance liquid chromatography was the most sensitive for amphetamine. Immunoassays performed well when operating above then-specified cut-off concentrations but, because they are directed to quinalbarbitone showed reduced cross-reactivity with amylobarbitone, the barbiturate more commonly prescribed in the UK.
Erythrocyte Membrane Fatty Acid Composition in Hypercholesterolemia
Authors: Taylor A J
Published: February 2014

The fatty acid composition of the erythrocyte membrane was determined in 22 hypercholesterolaemic patients managed by dietary restriction, and compared with that of 22 normocholesterolaemic controls, roughly matched for age and sex with the patient group. The patients exhibited higher relative proportions of palmitic ( P<0·01) and stearic ( P<0·005) acids and lower relative proportions of linoleic acid ( P<0·05) in the erythrocyte membrane, compared with controls, which could be due to presumed dietary differences between the groups. In the patients, the degree of hypercholesterolaemia was poorly correlated with erythrocyte linoleic acid. Measurement of erythrocyte linoleic acid might prove useful in the routine management of hypercholesterolaemia.
Fresh Haemolysis Interferes with Blocked P-Nitrophenylmaltoheptaoside Amylase Methods
Authors: Gosling Peter , Zareian Mehran
Published: February 2014

Two commercial amylase methods which employ p-nitrophenol derivatives of blocked maltoheptaosides suffer from negative interference due to fresh haemolysate. Specimen storage at room temperature, or pre-incubation at 37°C or 57°C removes the effect. Incubation of amylase reagent at 37°C with fresh haemolysate where the final haemoglobin concentration was 0·011 g/L, showed a rapid fall in absorption around 414 nm which became stable after 150 min. Since p-nitrophenol, the product of the amylase reaction, is measured at 405 nm it is concluded that the negative interference from fresh haemolysis is due to the transitory fall in absorption around 405 nm. It is recommended that amylase measurements using this technique, particularly those performed as an emergency, should not be done on haemolysed specimens.
Normal Red Cell Magnesium Concentrations and Magnesium Loading Tests in Patients with Chronic Fatigue Syndrome
Authors: Hinds G , Bell N P , McMaster D , McCluskey D R
Published: February 2014

Red blood cell magnesium concentrations were measured in samples from 89 patients who fulfilled the diagnostic criteria for chronic fatigue syndrome and the results compared to those found in an age and sex matched group selected from the normal population. No significant difference was found. Six patients were further investigated using a magnesium loading test to determine if there was any evidence of magnesium deficiency associated with this disorder. None was found. There is therefore no indication for the use of magnesium therapy in the management of this condition.
Expression of Gonadotropin-Releasing Hormone Receptor in Human Epithelial Ovarian Carcinoma
Authors: Imai Atsushi , Ohno Tsukasa , Ohsuye Kazuhiro , Tamaya Teruhiko
Published: February 2014

We have previously demonstrated the presence of gonadotropin-releasing hormone (Gn-RH) messenger ribonucleic acid (mRNA) in epithelial ovarian carcinoma. In this study, the expression of Gn-RH receptor (Gn-RHR) was investigated in human ovarian carcinoma and human ovarian carcinoma cell line. Gn-RHR was determined by [3H] Gn-RH binding assay. Gn-RHR mRNA was determined by reverse transcription-polymerase chain reaction using oligonucleotide primers synthesized based on published human Gn-RHR sequence.

Specific Gn-RH binding sites were shown to be present in plasma membrane isolated from five ovarian mucinous cystadenocarcinoma samples and one serous cystadenocarcinoma ( Kd = 15·3 ± 8·08 nmol/L). Gn-RHR mRNA was detected in four mucinous cystadenocarcinoma specimens, one serous cystadenocarcinoma, and SK-OV-3 cells, but not in white blood cells. These results suggest that Gn-RH may play an autocrine regulatory role in the growth of ovarian carcinoma.
The Long-Term Stability in Whole Blood of 14 Commonly-Requested Hormone Analytes
Authors: Diver M J , Hughes J G , Hutton J L , West C R , Hipkin L J
Published: February 2014

Concentrations of 14 commonly-requested plasma hormones were measured in octuplicate in each of six subjects to determine their stability when unseparated from red cells for periods up to 1 week. Most of the analytes were stable when stored in this way and although statistically significant changes were recorded, in the great majority of cases the changes seen would have no bearing on the clinical interpretation of the result. In the light of these findings, we would confidently report results of analyses for these hormones in plasma that had remained in contact with red cells at ambient temperature for long periods of time.
D-Dimer Tests Detect Both Plasmin and Neutrophil Elastase Derived Split Products
Authors: Seitz R , Lerch L , Immel A , Egbring R
Published: February 2014

Both plasmin and elastase, a protease released from neutrophil granulocytes, are known to degrade fibrin(ogen). This raises the possibility that elevated plasma levels of split products such as D-dimer may in part result from elastase action. After incubation in vitro of fibrinogen and fibrin clots with elastase, a clear-cut increase of D-dimer immunoreactivity was demonstrated by two commercial ELISA kits. In the plasma of 79 patients with inflammatory bowel disease, D-dimer values measured by one of the ELISA kits were correlated significantly not only with markers of thrombin and plasmin activation, but also with elastase-α1-antitrypsin complexes ( r = 0·3555; P = 0·014). Thus, the findings of this study suggest that indeed the D-dimer levels in patients with inflammatory disorders are influenced by neutrophil elastase. New tests discriminating effects of activated haemostasis from proteolysis by neutrophil enzymes might be helpful in differential diagnosis and monitoring of therapy.
Choice of Time for Urine Collection for Detecting Early Kidney Abnormalities in Hypertensives
Authors: Zuppi C , Baroni S , Scribano D , Salvo S Di , Musumeci V
Published: February 2014

The aim of this study was to determine the most appropriate urine collection for detecting differences in the excretion rates of albumin, γ glutamyl transpeptidase (GGT) and N-acetyl-β-D-glucosaminidase (NAGA) between normotensive subjects and hypertensive patients on treatment. Twenty treated hypertensive patients, mean (SEM, standard error of mean) age; 52·2 (6·2) years and 20 normotensive subjects, mean age 49·2 (4·2) years, were studied in a consecutive sampling design. Urinary excretion rates of albumin, GGT and NAGA were determined in consecutive timed urine samples collected overnight and during 3–5 h the next morning. Mean (SEM) overnight excretion rates for albumin, GGT and NAGA for normotensive subjects were 11·05 (1· 18) μg/min, 17·00 (2·20)mU/min and 6·55 (0·39) mU/min, respectively, which were significantly lower than those of hypertensive subjects which were 20·77 (2·14) μg/min, 21·84 (1·65) mU/min and 10·92 (0·87) mU/min, respectively ( P < 0·05). The mean (SEM) percentage increases in urinary albumin, GGT and NAGA in morning urine collections of normotensive subjects of 15·22 (3·88)%, 34·04 (6·45)% and 11·54 (3·63)%, respectively were significantly lower than 107·03 (15·04)%, 121·96 (16·71)% and 72·75 (7·50)% found in hypertensive patients ( P < 0·05). These data suggest that were urinary albumin and tubular enzyme excretion to be used as correlates of hypertensive renal damage, ambulatory urine collections may be more sensitive than overnight collections.
Rapid Troponin T Measurement in Whole Blood for Detection of Myocardial Damage
Authors: Collinson P O , Thomas S , Siu L , Vasudeva P , Stubbs P J , Canepa-Anson R
Published: February 2014

A dry chemistry system for rapid qualitative measurement of cardiac troponin T in whole blood, serum, EDTA and lithium heparin plasma was studied in 197 admissions to the coronary care unit and general wards of a typical district general hospital for whom troponin T was requested. This included patients with unexplained collapse, acute dysrythmia or elevated creatine kinase of unknown origin. EDTA whole blood and plasma proved the most satisfactory sample matrices. Lithium heparin whole blood was equally appropriate but lithium heparin plasma gave a false negative result. Serum was an unsatisfactory sample material. Comparison with the conventional wet chemistry quantitative enzyme-linked immunosorbent assay showed a positive bias for EDTA plasma, particularly in the range 0–1 μg/L and a significant negative bias for lithium heparin plasma. There was no difference between serum from plain or gel separator tubes. The whole blood method allows troponin T measurement to be performed rapidly and simply in the laboratory, either as an emergency test to alter patient management, or for those laboratories that wish to offer troponin T for selected cases but do not have the ability to measure troponin T quantitatively.
Determination of Total and Herpes Simplex Virus Specific Monomeric and Dimeric IgA in Serum and Cerebrospinal Fluid by Ultracentrifugation
Authors: Öhman Sten , Ernerudh Jan , Roberg Magnus , Forsberg Pia
Published: February 2014

An improved method is described for differentiating between monomeric and dimeric total and herpes simplex virus (HSV) specific IgA by ultracentrifugation in sucrose gradient, using recovery and quantitative analysis of the fractions obtained. Calculation of monomeric and dimeric IgA was based on IgG as an internal standard. Intrathecally produced monomeric and dimeric IgA were judged by calculating IgA indices for each form. A new type of formula indicating relative over-production of dimeric compared with monomeric IgA (IgA dimeric-monomeric index) is suggested.

The method was applied to serum and cerebrospinal fluid (CSF) from three patients with HSV encephalitis. The index for monomeric as well as dimeric IgA was high during the acute phase of the disease, indicating intrathecal synthesis of both molecular forms. One year after onset, there was no detectable HSV-specific IgA in CSF: Both molecular forms, however, remained in serum. The amount of dimeric compared with monomeric IgA was high during the acute phase, and subsequently decreased after successful treatment.

A new finding was the detection of HSV-specific IgA heavier than dimeric IgA in serum one year after onset of the disease. These components may be tetrameric IgA, or immune complexes containing IgA.
A Comparative Study of Six Commercial Lipoprotein(a) Assays in Seventeen Laboratories within the British Isles
Authors: Mackness Michael I , Bhatnagar Deepak , Weiringa Gilbert , MBewu Anthony , Haynes Barbara , Durrington Paul N
Published: February 2014

Seventeen laboratories in the British Isles participated in a study to compare six different commercially available immunoassays for serum lipoprotein(a) (Lp(a)) and to establish reasons for the variations in the measurement of serum Lp(a) concentrations. Pooled serum was distributed neat and after dilution at a central laboratory. In addition, the central laboratory sent unpooled serum sampled monthly from six healthy volunteers to each of the participating laboratories for 12 months.

The assays all gave linear dilution curves which were parallel, although the reported values varied twofold. There were major differences in the values assigned to different manufacturers' calibrants which was not explained by whether the units employed were whole Lp(a), the protein moiety of Lp(a) or simply apolipoprotein(a). The coefficient of variation for the reported value of Lp(a) over 12 months was 33%. The component variation was 10% after adjustment for inter-laboratory and intra-laboratory variation. Some individuals clearly had a greater tendency to variable serum Lp(a) concentrations than others, but all the assays responded to this in the same way.

Thus, the assays tested probably measured the same analyte. The problem of calibration could largely be addressed if agreement were reached by the manufacturers. Even with improvements in analytical precision it should be realized that multiple measurements of serum Lp(a) levels are necessary if the true mean value is to be appreciated. Individuals showing wide variation in serum Lp(a) may reward further study if its role is to be established.
Cardiac Troponin I and T Concentrations in Patients with Cocaine-Associated Chest Pain
Authors: McLaurin Mary , Apple Fred S , Henry Timothy D , Sharkey Scott W
Published: February 2014

Patients with cocaine-related chest pain with electrocardiographic (ECG) abnormalities are often admitted to rule out acute myocardial infarction (AMI). Cardiac troponin I and T should be superior to measurement of creatine kinase (CK)—MB for detecting cardiac injury in patients with coexisting skeletal muscle injury. We prospectively evaluated 19 consecutive patients with acute chest pain related to cocaine use who were hospitalized to rule out AMI. The admission ECG was abnormal in 16 of 19 patients. Total CK and CK—MB were elevated during the hospital course in 14 and 3 patients, respectively. Cardiac troponin I and cardiac troponin T levels were within normal limits in all patients demonstrating that recent myocardial injury did not occur. Clinically, no patient had an AMI. Cocaine-induced thoracic skeletal muscle injury or transient cocaine-induced coronary vasospasm should be considered as alternative sources of chest pain in these patients.
Cardiac Troponin T Release into Plasma after Acute Myocardial Infarction: Only Fractional Recovery Compared with Enzymes
Authors: Kragten Johannes A , Hermens Wim Th , van Dieijen-Visser Marja P
Published: February 2014

After acute myocardial infarction (AMI) cardiac enzymes and proteins are released into plasma and are used as biochemical markers of cardiac muscle injury. We studied the completeness of the release of troponin T, a cardiac protein that is largely bound to myofibrillar structures and compared it with the release of cytoplasmic cardiac enzymes in 22 patients with AMI, who were treated with thrombolytic therapy.

Creatine kinase (CK; EC 2.7.3.2), hydroxybutyrate dehydrogenase (HBDH), lactate dehydrogenase (LDH; EC 1.1.1.27) and troponin T were assayed serially in plasma samples obtained frequently and for at least 168 h after the start of thrombolytic therapy. Cumulative release of enzymes and troponin T in plasma were calculated by using a two-compartment model for circulating proteins.

In order to express the cumulative plasma releases in gram equivalents (g-eq) healthy myocardium per litre plasma (infarct size), we determined HBDH, LDH and total troponin T contents per gram net weight of tissue in 17 human hearts obtained post-mortem from patients who died from non-cardiac causes. Mean (SD) tissue contents per gram wet weight of, respectively, 156 ± 25 U/g, 385 ± 59 U/g and 234 ± 65 μg/g were found.

For the cardiac enzymes CK, HBDH and LDH the mean (SEM, n = 22) total release over 72 h, was, respectively, 5·9 ± 1·5, 5·9 ± 1·6 and 6·1 ± 1·7 g-eq/L. There was no further increase after 72 h and the differences between enzymes were not significant. The mean (SEM) cumulative troponin T release, expressed in gram equivalents of myocardium per litre of plasma was only 0·30 ± 0·09 g-eq/L after 72 h and 0·51 ± 0·61 g-eq/L after 168 h. After 72 h total recovery of troponin T in g-eq/L was only 5% and after 168 h only 8·5% of the total recovery of cytoplasmic cardiac enzymes after 72 h.

Cumulative troponin T release after 72 h and after 168 h correlates well with infarct size, estimated from cumulative cytoplasmic enzyme release. However, quantification of infarct size should preferably be performed from plasma release curves of cytoplasmic cardiac enzymes or proteins in order to prevent underestimation of infarct size, caused by incomplete release of the non-cytoplasmic proteins.
β-Hexosaminidase Isoenzymes A and B in Middle-Aged and Elderly Subjects: Determinants of Plasma Levels and Relation to Vascular Disease
Authors: Hultberg B , Isaksson A , Lindgren A , Israelsson B , Brattström L
Published: February 2014

Plasma/serum β-hexosaminidase (Hex) activity is known to be increased in chronic alcoholism, liver disorders, pregnancy and diabetes mellitus. Hex activity also shows an association with risk factors for vascular disease and heredity for arteriosclerosis. There are several isoenzymes of Hex. Using an enzyme immunoassay for Hex isoenzymes (Hex A and Hex B) we studied possible determinants of Hex isoenzymes and their relation to vascular disease in randomly invited ( n = 244) 35–95-year-old men and women.

In both sexes there were significant age-related increases in Hex activities and men exhibited higher activity of both isoenzymes. Both Hex isoenzymes correlated with age, systolic blood pressure, serum triglycerides and liver enzymes, whereas Hex A was distinguished from Hex B by its stronger correlation with blood glucose. In multiple linear regression analysis Hex A was explained to 20·7% by blood glucose, age, serum aspartate aminotransferase and glutamyl transpeptidase. Hex B was explained to 14% by age, serum glutamyl transpeptidase and serum triglycerides. There was no significant increase in Hex isoenzymes in subjects with hypertension, diabetes mellitus or myocardial disease, nor did current smokers exhibit any increase of these enzymes compared to non-smokers. The main conclusion is that liver function, as reflected by the level of liver enzymes and glucose metabolism, is the major determinant for Hex isoenzymes in plasma.
Sex Steroids Regulate the Expression of Plasminogen Activator Inhibitor-1 and its mRNA in Fibroblasts Derived from Uterine Endometrium
Authors: Fujimoto Jiro , Hori Masashi , Ichigo Satoshi , Tamaya Teruhiko
Published: February 2014

In order to clarify a role of stromal cells in sex steroidal neovascularization, plasminogen activator inhibitor (PAI)-1 [an inhibitor of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA)] and its messenger ribonucleic acid (mRNA) were analysed in fibroblasts derived from uterine endometrium as a model for endometrial stromal cells under the influence of sex steroids. The determinations were carried out by an enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction-Southern blotting, respectively.

In the fibroblasts, either estradiol or progestogens (progesterone, medroxy progesterone acetate or 17α-hydroxyprogesterone) induced expressions of PAI-1 and its mRNA, and their combination further increased their expression by approximately twofold. PAI-1 from endometrial stromal cells under the influence of sex steroids might contribute to endometrial neovascularization through its effect on endothelial cells in endometrial vessels.
Increased Mean Platelet Volume after Oestrogen Replacement Therapy
Authors: Ranganath L R , Christofides J , Semple M J
Published: February 2014

The effect of hormone replacement therapy (HRT) on platelet size was examined in 38 post-menopausal women before and at end of a 6 week period of HRT. Subjects were treated with cyclical L-norgestrel 75 mg daily from days 17 to 28 of a 28-day cycle combined with continuous conjugated equine oestrogens 0.625 mg daily. Platelet-rich plasma was obtained to measure platelet indices by Coulter analysis. Plasma measurements of luteinizing hormone, follicle stimulating hormone and 17β-oestradiol were measured by immunoassays. Platelet membrane fatty acids were measured by gas-liquid chromatography. A significant reduction in platelet membrane linoleic acid, di-homo-γ-linoleic acid and arachidonic acid of 8.1%, 14.3% and 17.8%, respectively was noted after 6 weeks of HRT ( P < 0.01). There was an increase in the platelet count (not significant) and platelet volume (MPV) ( P < 0.05) after 6 weeks of hormone therapy. HRT appears to increase mean platelet volume which may indicate an increase in platelet reactivity. There was no correlation between the changes in mean platelet volume and membrane fatty acid changes in platelets after such therapy.
Clinical Indications for the use of Urinary Steroid Profiles in Neonates and Children
Authors: Honour J W , Brook C G D
Published: February 2014

For a number of rare adrenal disorders, some of which are life threatening in childhood, laboratories need access to specialist endocrine investigations. Measurements of hormones in blood samples may be diagnostic in some cases but not all of the requisite steroid hormone assays are available. Multiple plasma steroid measurements may be required to prove the nature of a steroid biosynthetic disorder but in newborn children immunoassays, performed without prior solvent extraction, can be misleading. A urine steroid profile by gas chromatography coupled with mass spectrometry examines many steroid metabolites simultaneously and provides specific diagnostic information. A urine steroid profile can provide precise information of the secretory nature of tumours and causes of virilization, salt loss and hypertension often from a spot urine sample rather than a 24 h collection. However, a steroid profile is not helpful in making a diagnosis in neonatal genetic males with poorly developed genitalia.
Structural Changes in Oxidative Modification of Low-Density Lipoprotein: Investigation Using Lipid Peroxidation Products, Surface Charge, and Spectrophotometric Patterns
Authors: Okada Masahiko , Ito Yasuki , Inano Koichi , Miida Takashi , Matsuto Takayuki
Published: February 2014

It is well recognized that oxidative modification of low-density lipoprotein (LDL) accelerates atherogenesis of the arterial vascular wall. In this study, we examined the relationship between various methods of measuring the extent of oxidation, namely lipid peroxidation products, surface charge, and spectrophotometric patterns. LDL was isolated from fresh human normal plasma by centrifugation and was oxidized by incubating with copper ions. Apolipoprotein B was isolated from the LDL solution. We also prepared artificial lipid particles composed of cholesterol linolenate, triolein, and phosphatidylcholine. Our results suggest that lipid peroxidation begins drastically in 30–60 min, while the abolition of the positive charge on apoliproproteins is accelerated after 60 min. We found a characteristic change in the spectrophotometric pattern during the process and conclude that the spectrophotometric absorption ratio at 232 and 203 nm is a useful measure of in vitro oxidation of LDL.
Adaptation of the Nitrate Reductase and Griess Reaction Methods for the Measurement of Serum Nitrate plus Nitrite Levels
Authors: Giovannoni G , Land J M , Keir G , Thompson E J , Heales S J R
Published: February 2014

Nitrite and nitrate determinations in biological fluids are increasingly being used as markers of nitric oxide production. We have modified a nitrate reductase and Griess reaction method for the measurement of serum nitrate and nitrite in ultrafiltrated samples using a microtitre plate. The recoveries of nitrate and nitrite were 95% (range = 86–113%) and 100% (range = 92–109%), respectively. The intra and inter assay coefficients of variation for nitrate plus nitrite in the concentration range 40–50μM were 9·1% and 7·8%, and in the concentration range of 2·5–10μM 23·4% and 25·5%, respectively. At its lower limit the assay is able to detect 125 pmoles of nitrate plus nitrite in 50μL of sample (2·5μmol/L). A mean serum nitrate plus nitrite level of 32·8μmol/L (SD 12·3) was measured in 24 healthy adult volunteers (12 men and 12 women), no age or sex differences were noted.
Macroprolactinaemia: Contribution to Hyperprolactinaemia in a District General Hospital and Evaluation of a Screening Test Based on Precipitation with Polyethylene Glycol
Authors: Fahie-Wilson M N , Soule S G
Published: February 2014

For a period of 12 months all samples submitted for serum prolactin (PRL) assay and with PRL>700mU/L were examined by gel filtration chromatography. In 17 (25%) of 69 samples we found macroprolactin. The Delfia and Immuno 1 immunoassay systems gave similar PRL results with samples containing macroprolactin whereas the ACS 180 system gave lower results. With the Delfia and Immuno 1 systems samples containing substantial quantities of macroprolactin showed low recovery of PRL after precipitation with polyethylene glycol 6000 (PEG 6000) and this technique can be used as a screening test for macroprolactinaemia. We conclude that macroprolactinaemia is a common phenomenon and, in assays which detect this species, is a common cause of hyperprolactinaemia. Macroprolactinaemia may contribute to the difficulty in establishing an upper limit of the reference range for serum PRL. In our experience, patients with macroprolactinaemia do not exhibit features of the hyperprolactinaemia syndrome and it is important to recognize macroprolactin as the cause of hyperprolactinaemia to avoid unnecessary investigation and treatment.
Atypicality Revisited: Further Data on the Effectiveness of the Mahalanobis Distance in Down's Syndrome Screening
Authors: Reynolds T M
Published: February 2014

Further data suggesting that assessment of atypicality may be a valuable addition to Down's syndrome screening is presented, based on results from 1521 unaffected pregnancies and 190 chromosomally abnormal pregnancies. For a 1 % increase in false positive rates (over the Down's screening-related false positives), it is estimated that the detection of non-trisomy 21 abnormalities may be enhanced by approximately 40%. These false positive and detection rates are similar to previous reports for specific trisomy 18 screens. Further work is necessary to prove whether a specific trisomy 18 screen, or an atypicality screen is preferable.
New Enzymatic Assay with Urea Amidolyase for Determining Potassium in Serum
Authors: Kimura Shigeki , Iyama Shigeru , Yamaguchi Yoshihisa , Hayashi Sadao , Fushimi Ryo , Amino Nobuyuki
Published: February 2014

We developed a new simple assay for potassium ion in serum using urea amidolyase (UAL) from yeast sp. The method is based on activation of the enzyme by potassium ion. We eliminated endogenous ammonium ion by use of glutamate dehydrogenase (GLDH), and then monitored the production of ammonium ion by UAL, urea, ATP, bicarbonate and magnesium ions. Ammonium ion was produced proportional to the potassium ion concentration and was determined by adding GLDH to produce NADP+ in the presence of 2-oxoglutarate and NADPH. We monitored the change of absorbance at 340 nm. The inhibitory effect of calcium ion to this assay was eliminated by adding glycoletherdiamine-N, N, N', N'-tetraacetic acid to the reaction. The within-assay coefficients of variation (CV) of this method were 0·99–1·55% ( n = 10) at 3·32–6·18mmol/L. Day-to-day CVs ranged from 1·49% to 2·46%. The analytical recovery was 96–108%. The correlation coefficient between the values obtained by our method ( y) and those by the ion-selective electrode (ISE) method ( x) was 0·994 ( y = 1·032x-0·166 mmol/L, S y·x = 0·110, n = 100). The presence of bilirubin, haemoglobin or other ions did not affect this assay, confirming the usefulness of this assay for clinical purposes.
Analysis of Urinary Pseudouridine by Micellar Electrokinetic Capillary Chromatography
Authors: Evans M D , Perrett D , Lunec J , Herbert K E
Published: February 2014

We describe a capillary electrophoresis procedure, using uridine as an internal standard, for the analysis of urinary pseudouridine following solid-phase extraction. This method retains the advantages of existing chromatographic techniques but has superior resolving power and is technically less demanding. The standard curves were linear and reproducible with a detection limit of 60 fmol; chromatographic analysis was complete in under 10min. Injection variability was <5% and multiple independent analyses of the same urine sample for pseudouridine concentration gave coefficients of variation of < 10%. The mean (SD) urinary pseudouridine level in 18 healthy subjects was 16·1 (2·l)nmol/μmol creatinine. For a limited group of subjects where samples were taken more frequently, intra-individual variation averaged 27.5% reflecting variable excretion.
APO E Genotype and Familial Hypercholesterolaemia
Authors: Duly E B , Ward A J , Kirk C W , Nevin N C , Trinick T R , Nicholls D P , Young I S , Graham C A
Published: February 2014

Apolipoprotein E genotypes were measured in 83 patients with familial hypercholesterolaemia (FH) and in 175 blood donor controls. Following DNA extraction from peripheral blood, each sample was genotyped for the Apo E polymorphism by polymerase chain reaction. No significant differences were found in the levels of the ε2 and ε3 alleles between the two groups, while the ε4 allele was approximately twice as prevalent in the FH patients as in controls ( P = 0·006, df = 1). Of the FH patients, 8·4% were homozygous for the ε4 allele while this genotype was rare in controls ( P = 0·009, df = 1). These results suggest that the ε4 allele is over represented in the FH population and may contribute to increased cholesterol levels and consequent vascular disease.
Poor Glycaemic Control is Associated with Reduced Serum Free Radical Scavenging (Antioxidant) Activity in Non-Insulin-Dependent Diabetes Mellitus
Authors: Maxwell S R J , Thomason H , Sandler D , LeGuen C , Baxter M A , Thorpe G H G , Jones A F , Barnett A H
Published: February 2014

The diabetic patient is at significantly increased risk of developing vascular disease. Its aetiology may involve oxidative damage by free radicals and protection against such damage can be offered by radical-scavenging antioxidants. We investigated whether there was a relationship between glycaemic control as assessed by measurement of glycated haemoglobin (HbAlc) and serum antioxidant status in a population of 118 diabetic outpatients with either insulin-dependent or non-insulin-dependent diabetes. Amongst patients with non-insulin-dependent diabetes mellitus there was a significant inverse correlation between levels of glycated haemoglobin and total free radical scavenging activity ( r = −0·456, P <0·0001). This association resulted primarily because of a similar correlation with uric acid ( r = −0·421, P = 0·0003). There was also a weak inverse correlation with vitamin A but no significant association with vitamin C or vitamin E levels. There were no significant associations found amongst the patients with insulin-dependent diabetes. These results indicate that poor diabetic control is associated with reduced serum free radical scavenging (antioxidant) activity in non-insulin-dependent diabetes mellitus. By implication improved glycaemic control may preserve serum antioxidant status in diabetes.
Changes in Serum Osteocalcin Levels in the Follow-Up of Kidney Transplantation
Authors: Bonnin M R , Gonzalez M T , Griñó J M , Cruzado J M , Bover J , Martinez J M , Navarro M A
Published: February 2014

Serum osteocalcin, total alkaline phosphatase, intact parathyroid hormone (PTH), creatinine, calcium, and phosphate were determined in 23 kidney cadaveric allograft recipients, immediately before and 0·5, 1, 3 and 6 months after surgery. Immunosuppressive treatment was based on low doses of corticosteroids and cyclosporin combined with antilymphoblast globulin. The decrease in serum creatinine was accompanied by falling PTH concentrations. Serum osteocalcin levels were higher than normal before kidney transplantation and diminished at 0·5 and 1 month after surgery. Significant increases in serum osteocalcin concentrations were observed 3 and 6 months after kidney transplantation with a significant correlation with alkaline phosphatase levels. The increase in serum osteocalcin levels observed in our transplanted patients is not related with a parallel increase in serum creatinine levels nor with an increment in PTH levels; it seems to reflect an increase in the osteoblastic activity, which is not altered by steroid therapy.
Difficulties in Evaluating Urinalysis following Combined Pancreas–Kidney Transplantation
Authors: Bernard Dirk R , Delanghe Joris R , Langlois Michel R
Published: February 2014

Combined pancreas–kidney transplantation has been introduced in the treatment of patients with type 1 diabetes and renal failure 20 years ago. By 1985 374 combined pancreas–kidney transplantations had been reported to the International Pancreas Transplant Registries.1 Surgical drainage of the transplanted exocrine pancreas into the urinary bladder solves most of the postoperative problems encountered with the exocrine secretions. Furthermore, monitoring of pancreatic enzyme (amylase) activity in urine has been shown to be useful in diagnosis of rejection of the pancreatic graft.2 However, little attention has been paid to the biochemical consequences of high activities of proteolytic pancreatic enzymes on the determination of urinary proteins. The present case illustrates the difficulties in interpreting proteinuria in patients with combined pancreas–renal transplant with pancreaticocystostomia. In the propositus, interpretation of the urinary protein electrophoresis is hampered by the presence of pancreatic juice proteins and peptides originating from digestion of proteins by activated pancreatic enzymes. Results of immunochemically determined marker proteins ([micro]albumin, transferrin, β2-microglobulin) are unreliable due to digestion by pancreatic enzymes.
Accuracy of Devices Used for Self-Monitoring of Blood Glucose
Authors: Johnson Roger N , Baker John R
Published: February 2014

We measured the inaccuracy of 17 home blood glucose monitors (two visually read, eight colorimetric and seven amperometric). Using strips from a single batch, blood glucose measurements were performed by three medical laboratory technologists on at least 50 capillary blood specimens from patients attending two diabetes clinics. Additional capillary blood was deproteinized and assayed with hexokinase to give a whole blood glucose result. A dedicated glucose analyser was also studied to cross-validate the methodology. At a mean glucose concentration of about 9 mmol/L, monitor readings differed from the reference results by −5.1 to + 19.5% with three systems failing to meet the American Diabetes Association guideline for total error of less than 15%. This problem would be alleviated by manufacturers adopting a common policy on calibration and on reporting as a plasma or whole blood value.
Log-Jam in Acid-Base Education and Investigation: Why Make it so Difficult?
Authors: Hooper James , Marshall William J , Miller Arthur L
Published: February 2014

Medical students frequently have difficulty in interpreting acid-base data particularly when pH values are used. The difficulty persists when students qualify and has implications for the safe management of patients who require investigation of acid-base status. Simplification of tuition is required together with a change of practice in the reporting of acid-base data by the laboratories. To improve understanding, we recommend that the teaching and reporting of acid-base status should be changed to use [H+] instead of pH, and a greater emphasis placed on the logical interpretation of primary measurements—that is [H+] and PCO2-with less reliance on derived variables.
The Effect of Benign and Malignant Liver Disease on the Tumour Markers CA19-9 and CEA
Authors: Maestranzi S , Przemioslo R , Mitchell H , Sherwood R A
Published: February 2014

The serum concentrations of CA19-9 and carcinoembryonic antigen (CEA) were measured in 150 consecutive patients with histologically proven liver disease admitted to a liver unit for transplant assessment. A significant proportion of the cases studied had a CA19-9 above the upper limit of the reference range (35 kU/L): alcoholic liver disease (73%), primary sclerosing cholangitis (61%), primary biliary cirrhosis (60%), chronic hepatitis B (71%), chronic hepatitis C (84%), autoimmune hepatitis (36%) and hepatocellular carcinoma (54%). CEA was only elevated in a small proportion of the patients with benign liver disease and the degree of elevation was small (15-37 μg/L). Significantly raised CEA was observed in two patients (15%) with hepatocellular carcinoma. Statistically significant correlations were observed between the serum CA19-9 concentration and standard parameters of liver dysfunction: positive correlations with aspartate aminotransferase, alkaline phosphatase and bilirubin and negative correlations with albumin and γ-glutamyltransferase. Positive relationships were also observed between CA19-9 and both CEA and creatinine. Both increased production of CA19-9 from biliary epithelial cells and decreased clearance due to cholestasis may be contributing to the elevation of CA19-9 in the bloodstream. Our data indicate that caution is needed in the interpretation of CA19-9 results in the presence of liver dysfunction.
Sensitive Assays for Urinary Retinol-Binding Protein and β-2-Glycoprotein-1 Based on Commercially Available Standards
Authors: Lapsley M , Akers K , Norden A G W
Published: February 2014

Measurements of urinary retinol-binding protein (RBP) and β-2-glycoprotein-1 (β2G1) provide sensitive indicators of proximal renal tubular malfunction. β2G1 is very stable in urine but RBP, which is much less stable, has been more extensively studied. We have designed two similar immunoassays allowing measurement of both proteins from one urine dilution. The assays both use widely available commercial standards and permit accurate measurement throughout most of the reference range. We measured both proteins in the urine of 70 healthy adults and 80 healthy children aged between three and 16 years, expressing the results as a ratio to creatinine concentration. Using the 98th centile as the upper reference limit, adults excreted up to 17 μg/mmol RBP (median 8) and up to 30 μg/mmol β2G1 (median 15) with no difference between the sexes. Children had different ranges to adults with excretion of up to 22 μg/mmol RBP (median 10) and up to 80 μg/mmol β2G1 (median 24).
Endothelin-1 Production by Human Synoviocytes
Authors: Yoshida Hiroshi , Imafuku Yuji , Ohhara Morihiro , Miyata Masayuki , Kasukawa Reji , Ohsumi Kazuoki , Horiuchi Junko
Published: February 2014

Immunoreactive (ir)-endothelin (ET)-l concentrations in serum samples and synovial fluids from patients with rheumatoid arthritis were higher than concentrations in sera obtained from healthy volunteers. No significant difference in ir-ET-1 concentrations in synovial fluid was observed between rheumatoid arthritis patients and osteoarthritis patients. Cultured fluids of synovial cells collected from synovial tissues and leucocytes from synovial fluids of rheumatoid arthritis patients were studied to determine the origin of ir-ET-1 in synovial fluids. Ir-ET-1 was detected in the cultured fluids of synovial macrophage-like type A cells, but not in those of fibroblast-like type B cells from the synovial tissues or leucocytes from the synovial fluids. Longitudinal studies showed that the ir-ET-1 concentration in the cultured fluid reached a peak around 24 h after starting the culture. ET-1 secreted from macrophage-like synoviocytes may be involved in the pathogenesis of inflammatory arthritis.