bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of Four Serum Markers of Fibrosis in the Diagnosis of Cirrhosis
Authors: Fabris Carlo , Falleti Edmondo , Federico Edda , Toniutto Pierluigi , Pirisi Mario
Published: February 2014

C-terminal peptide of procollagen I, N-terminal peptide of procollagen III, collagen IV and serum prolyl hydroxylase were measured in 100 patients with cirrhosis and 71 patients with noncirrhotic chronic liver disease. Patients with cirrhosis had significantly higher mean values of prolyl hydroxylase, collagen IV, N-terminal peptide of procollagen III and C-terminal peptide of procollagen I as compared to noncirrhotic patients. This difference was maintained for collagen products even after stratification for alcohol intake, although all markers of fibrosis were higher in alcoholics. Stepwise logistic regression analysis showed that collagen IV, and N-terminal peptide of procollagen III were independently associated with cirrhosis. Receiver-operating characteristic (ROC) curves showed that collagen IV and N-terminal peptide of procollagen III perform more efficiently than C-terminal peptide of procollagen I and prolyl hydroxylase in identifying cirrhosis.
Elevated Concentrations of Interleukins and Leukotriene in Response to Mycobacterium Tuberculosis Infection
Authors: El-Ahmady O , Mansour M , Zoeir H , Mansour O
Published: February 2014

There is significant research in the role of interleukins in lung disease, as the cytokines are important mediators in the host response to mycobacterium tuberculosis infection. Plasma from patients with pulmonary tuberculosis (TB) and healthy controls were investigated for their content of granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-6 (IL-6) and leukotriene B4 (LTB4). LTB4 and IL-6 were measured by enzyme immunoassay after lipid extraction in the case of LTB4 while GM-CSF was measured by enzyme amplified sensitive immunoassay. Significantly elevated concentrations of IL-6 were found in far-advanced lesions of pulmonary tuberculosis patients, P < 0·05. However, nonsignificant increases of IL-6 were obtained in moderate lesions and minimal lesions compared to normal healthy subjects. Marked elevations of LTB4 were found in TB patients, the highest values being shown in patients with far-advanced lesions followed by moderately advanced and minimal lesions in relation to the mean value for normal healthy controls, P < 0·001 for all groups. 93% of the tuberculosis patients showed a higher level of LTB4 above the upper limit of the control group. In contrast there was no significant increase of GM-CSF in any of the TB subgroups. These results suggest that LTB4 and the interleukins may play a role in the pathogenesis of mycobacterium tuberculosis infection.
Serum Calcium and Vitamin D Status of Patients with Sickle Cell Disease in Curaçao
Authors: van der Dijs Fey P L , van der Klis Fiona R M , Muskiet Fred D , Muskiet Frits A J
Published: February 2014

We measured parameters of calcium homeostasis and vitamin D status in HbSS patients (median age 8 years, range 3–19; 8 females, 10 males) and matched HbAA controls living in the tropical island of Curaçao. Serum calcium concentration in HbSS patients [2·32(0·07) mmol/L] was lower (ANCOVA, P = 0·002) than that of HbAA controls [2·44(0·14)]. None of the subjects had hypocalcaemia. There were no differences in serum concentrations of phosphate, total protein, albumin, intact parathyroid hormone (PTH), 25-hydroxyvitamin D [87(27) nmol/L in patients, 86(15) nmol/L in controls) and 1,25-dihydroxyvitamin D. There were no significant relations between PTH and 25(OH)D. We conclude that vitamin D status of HbSS patients in Curaçao is adequate.
A Highly Sensitive Assay for Quantitation of Apolipoprotein B48 Using an Antibody to Human Apolipoprotein B and Enhanced Chemiluminescence
Authors: Smith Darrin , Proctor Spencer D , Mamo John C L
Published: February 2014

We describe a method for the rapid quantification of serum apolipoprotein B48 using a commercially available anti-apolipoprotein (apo)B antiserum and compare it to analytical sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) with coomassie blue R250 staining. The method described here eliminates the need for de-lipidation of samples and only requires a one-step overnight ultracentrifugation. Western-blotting and enhanced chemiluminescence (ECL) visualization of proteins was approximately 10 times more sensitive than coomassie staining and generally took no longer to complete than staining/destaining of SDS-PAGE gels. The sensitivity of the antiserum/ECL technique enabled quantitation of fasting apolipoprotein B48 which could not be resolved by SDS-PAGE and Coomassie staining.
Lens Lipid Peroxides and Glutathione Concentrations in Diabetic Cataract
Authors: Özmen D , Mutaf I , Özmen B , Mentes J , Bayindir O
Published: February 2014

This study aims to explore the role of reactive oxygen radicals in the genesis of diabetic cataract. Lipid peroxide (LPO) concentrations in senile ( n = 30) and diabetic ( n = 14) cataractous lenses, were determined as thiobarbituric acid-reactive substances (TBARS) by a method modified from Satoh and Yagi, and reduced glutathione (GSH) concentrations were measured according to Beutler. Lens LPO levels (mean, SD; nmol TBARS/g protein) were significantly higher in diabetics (107·54, 18·12) than senile cataractous subjects (53·54, 15·48) ( P < 0·0001). Lens GSH levels (mean, SD; nmol/g protein) showed no significant difference between diabetics (4·29, 2·05) and senile cataractous subjects (4·68, 3·12). These results suggest that free radical damage is more effective in the genesis of diabetic cataract than in senile cataract.
Microalbuminuria in Type 2 Diabetic Patients: A Prospective Follow-Up Study
Authors: Friis Thorkild , Pedersen Laurids R
Published: February 2014

We have studied 46 patients, 30 men and 16 women, with type 2 (noninsulin-dependent) diabetes in a follow-up period of 6–52 months (mean 30 months). The patients were consecutively entered in the study from the out-patient diabetic clinic. None had urinary tract infections nor proteinuria at entry. Investigations were done every 3 months during the first year and after that every 6 months. At entry 16 patients (35%) had microalbuminuria and a further 16 patients developed microalbuminuria and 16 proteinuria. The systolic blood pressure was higher in men with microalbuminuria compared to men without microalbuminuria. The glomerular filtration rate decreased with time for patients with microalbuminuria without change in plasma creatinine. The C-peptide concentration was higher in the hypertensive patients compared to non-hypertensive and the same was found for the triglyceride concentration. During the observation period the various complications increased in frequency (retinopathy, cardiomyopathy, neuropathy, angiopathy and hypertension) without significant relation to the presence of microalbuminuria or proteinuria. During the observation period nine patients died mainly due to cardiovascular events.
#Hyperamylasaemia in Asymptomatic HIV Patients
Authors: Foo Ying , Konecny Pamela
Published: February 2014

We studied serum amylase and its isoenzymes prospectively in 163 consecutive asymptomatic patients, 149 men and 14 women, infected with HIV and attending an HIV out-patient clinic. Six patients were receiving dideoxyinosine (DDI), a drug known to cause pancreatitis. No patient, however, had clinical signs suggestive of pancreatitis. Serum total amylase was increased in 39 of 163 patients (24%), in 11 of whom (28%), this was due to increased pancreatic (P) isoamylase alone, in 17 (42%) it was due to salivary (S) type alone and in six (17%) it was due to increase of both P and S fractions. In five patients (13%), macroamylase was detected. Pancreatic amylase was elevated in four of the six patients on DDI. The remaining two had macroamylase. Our results show that asymptomatic hyperamylasaemia is a common finding in HIV patients and that it appears to be heterogenous, i.e. elevation may be due to increase in P or S, both enzyme fractions or macroamylase. The high incidence of macroamylasaemia in HIV patients was an unexpected finding.
One-Step Enzyme-Linked Immunosorbent Assay (ELISA) for Plasma Fatty Acid-Binding Protein
Authors: Wodzig K Will H , Pelsers Maurice M A L , van der Vusse Ger J , Roos Werner , Glatz Jan F C
Published: February 2014

To allow a more rapid determination of heart-type fatty acid-binding protein (FABP) concentration in plasma a direct non-competitive (sandwich-type) ELISA was developed which uses high-affinity monoclonal antibodies to FABP. Total performance time of the one-step immunoassay is 45min. The standard curve was linear between 0·2–6μg/L, and the within-run and between-run coefficients of variations were below 6 and 11%, respectively. The serum FABP concentration measured in 79 healthy individuals was 1·6 (0·8) [mean (SD), range 0·3–5·0] μg/L. The assay can be used for rapid plasma or serum FABP measurement in the early diagnosis of acute myocardial infarction.
Effect of Simvastatin Therapy on Cell Membrane Cholesterol Content and Membrane Function as Assessed by Polymorphonuclear Cell NADPH Oxidase Activity
Authors: Day A P , Bellavia S , Jones O T G , Stansbie D
Published: February 2014

Cell membrane cholesterol is an important determinant of membrane fluidity. Changes in fluidity have important consequences for membrane function. Treatment of hypercholesterolaemia could therefore affect membrane function by reducing cell membrane cholesterol levels. The aim of this study was to determine whether treatment with simvastatin affects membrane cholesterol and the activity of the polymorphonuclear cell membrane enzyme NADPH oxidase. Blood was obtained from 12 hypercholesterolaemic patients before, and 6 weeks after, treatment with simvastatin, and from 20 normolipidaemic subjects. Cell cholesterol was in the unesterified form indicating that it was membrane-associated. Pretreatment mean cell cholesterol concentration in the hyperlipidaemics was higher ( p<0·05) than in the normolipidaemics [4·19fmol/cell, 95% confidence interval (CI) 3·38–5·05 versus 3·10fmol/cell, 95% CI 2·58 3·61]. There was a strong correlation between cell cholesterol content and NADPH oxidase lag phase ( Rs = 0·76, P<0·01). Cell cholesterol fell to 3·52fmol/cell (95% CI 2·77–4·28, P<0·05) following treatment and there was a correlation ( Rs = 0·61, P<0·05) between the reductions in cell cholesterol and lag phase.
Variation in Detection of VEGF in Maternal Serum by Immunoassay and the Possible Influence of Binding Proteins
Authors: Anthony F W , Evans P W , Wheeler T , Wood P J
Published: February 2014

Using radioimmunoassay (RIA) and a polyclonal antibody we have shown that maternal serum vascular endothelial growth factor (VEGF) is elevated during pregnancy. In contrast, a commercial VEGF ELISA utilizing a sandwich two-site immunoassay was unable to detect VEGF in 19 of the 20 maternal serum samples analysed. In addition, the recovery of exogenous VEGF added to the pregnancy samples was low or not recordable with the ELISA. Using RIA, 82–101% of the added VEGF was recovered. These differing results could be explained by the formation of VEGF-protein complexes that are detectable using RIA but undetectable with the ELISA. Our data imply that there is a substantial increase in circulating VEGF binding proteins during pregnancy. The increase in VEGF and its binding proteins during pregnancy may reflect important physiological events in the mother and feto-placental unit.
The Use of a Hemocue Blood Glucose Analyser in a Neonatal Unit
Authors: Leonard M , Chessall M , Manning D
Published: February 2014

Near patient testing for glucose is now a widely accepted procedure in hospital wards and clinics. However, in a neonatal ward where the detection of hypoglycaemia rather than hyperglycaemia is of paramount importance, it is more difficult to find a suitable glucose monitoring instrument. We compared two Hemocue blood glucose analysers (Hemocue Ltd) in our special care baby unit (SCBU) with the laboratory procedures and found that the Hemocue may overestimate the glucose by as much as 2·5mmol/L. In addition, Hemocue analysers are costly to run. We feel these analysers may be more useful in a general ward rather than in a SCBU.
Novel Instrumentation for Real-Time Monitoring Using Miniaturized Flow Systems with Integrated Biosensors
Authors: Freaney R , McShane A , Keaveny T V , McKenna M , Rabenstein K , Scheller F W , Pfeiffer D , Urban G , Moser I , Jobst G , Manz A , Verpoorte E , Widmer M W , Diamond D , Dempsey E , de Viteri F J Saez , Smyth M
Published: February 2014

A prototype miniaturized Total Chemical Analysis System (μTAS) has been developed and applied to on-line monitoring of glucose and lactate in the core blood of anaesthetized dogs. The system consists of a highly efficient microdialysis sampling interface sited in a small-scale extracorporeal shunt circuit (‘MiniShunt’), a silicon machined microflow manifold and integrated biosensor array for glucose and lactate detection with associated computer software for analytical process control. During in-vivo testing the device allowed real-time on-screen monitoring of glucose and lactate with system response times of less than 5 min, made possible by the small dead volume of the microflow system. On-line glucose and lactate measurements were made in the basal state as well as during intravenous infusion of glucose or lactate. The prototype μTAS is currently suitable for trend monitoring but refinements are necessary before application of the system for determination of individual lactate values.
Observations on the Relationships between Plasma Free Fatty Acids, Ketones and Bicarbonate in Acute Hyperglycaemia
Authors: Davidson D Fraser
Published: February 2014

Some of the initial biochemical findings, obtained from 141 randomly-selected cases of acute hyperglycaemia (admission plasma glucose >20 mmol/L) were examined. When viewed in terms of their initial plasma bicarbonate concentration, three groups were identifiable. Plasma concentrations of free fatty acids (FFA), acetone and the sum of 3-hydroxybutyrate (3OHB) and lactate were different between these groups. However, there were no differences in plasma glucose or lactate concentrations. It was further observed that the relationship between the plasma FFA/albumin molar ratio, and ketone concentration could be described by a rectangular hyperbola, and the initial anion gap was linearly related to the sum of the 3OHB and lactate concentrations.
Relationship between Lipoprotein (a) and Both Stroke and Carotid Atheroma
Authors: Markus Hugh S , Kapadia Rupal , Sherwood Roy A
Published: February 2014

In vitro studies provide mechanisms by which elevated lipoprotein(a) [Lp(a)] concentrations may promote both thrombosis and atherogenesis. Case-control studies have reported raised Lp(a) concentrations in patients with stroke, but prospective studies have failed to confirm the association. A potential confounding factor is that Lp(a) may rise acutely after stroke. We determined Lp(a) concentrations in 164 patients studied at least 21 days after stroke or transient ischaemic attack, and in 91 controls. In the patient group we correlated Lp(a) concentrations with both the degree of carotid stenosis estimated on duplex ultrasonography, and with stroke subtype (large vessel disease, lacunar infarction, and cardioembolic and unknown pathogenesis). There was no difference between Lp(a) concentration in cases and controls [median (quartiles) 0·10 (0·04, 0·39) versus 0·12 (0·04, 0·30) g/L, P = 0·34]. There was no difference in the proportion of cases compared with controls with a markedly elevated Lp(a) of > 0·4g/L (21·3 versus 16·5%, P = 0·34). There was non-significant trend towards higher median Lp(a) concentrations in women [median (quartiles) 0·16 (0·04, 0·32)g/L versus 0·12 (0·04, 0·28) g/L, P = 0·3]. In view of this trend we analysed the differences between cases and controls for each sex separately. Lp(a) concentrations in men were median (quartiles) 0·08 (0·04, 0·26)g/L in the 101 cases and 0·12 (0·04, 0·28) g/L in the 43 controls ( P = 0·6). Lp(a) concentrations in women were median (quartiles) 0·25 (0·04, 0·44) g/L in the 63 cases, and 0·16 (0·04, 0·32) g/L in the 48 controls ( P = 0·16). Within the patient group there was no difference between Lp(a) concentrations in the different stroke subgroups. There was no relationship between Lp(a) concentrations and mean percentage carotid stenosis ( rs = 0·14, P = 0·07). Our results suggest that in an unselected population of men studied more than 3 weeks post event there is no relationship between lipoprotein(a) concentrations and either stroke/transient ischaemic attack, or carotid atheroma. The relationship in women requires further study.
A Comparison of Three Procedures for the Detection of Bence–Jones Proteinuria
Authors: Wong W K , Wieringa G E , Stec Z , Russell J , Cooke S , Keevil B G , Lockhart S
Published: February 2014

A traditional electrophoretic procedure for detection of Bence–Jones proteinuria, employing Amido black stain on 200-fold concentrated urine, has been compared to two procedures employing highly sensitive protein stains not requiring prior urine concentration. All three procedures were carried out on 80 random urine samples screened for Bence–Jones proteinuria and 10 samples were provided by patients attending a myeloma clinic. A new procedure employing modified Coomassie brilliant blue stain on unconcentrated urine showed comparable sensitivity to the established procedure (82% versus 88%, respectively) and specificity (77% versus 74%, respectively), when assessed against immunofixation as a reference method. However, the new method is considerably quicker and cheaper. A second method, employing Gold stain, showed enhanced sensitivity (94% versus 88% for Amido black) but lower specificity (62% versus 74% for Amido black). However, this method is labour intensive and relatively expensive. Our data suggest that the procedure employing modified Coomassie brilliant blue may be a suitable alternative to the traditional procedure commonly used in many clinical laboratories.
The Measurement of Morphine in the Hair of Heroin Abusers
Authors: George S , Braithwaite R A
Published: February 2014

Several techniques have been described for the determination of morphine in hair as a method of monitoring past heroin use. However, although some of the techniques [notably radioimmunoassay (RIA)] may appear relatively simple to perform, any results obtained must be interpreted with caution. In this study, hair specimens from four known heroin abusers were sectionally analysed by a specific RIA for morphine. Prior to analysis, all hair sections were cleaned to remove any possible surface contamination. Five different hair digestion procedures were evaluated to determine the most effective method that could be used to liberate morphine from hair. The greatest analytical recovery was obtained by incubation with 1·0 M sodium hydroxide for 18 h at 55°C, neutralization with 1·0 M hydrochloric acid, and pH adjustment with 0·1 M phosphate buffer (pH 7·0). The morphine concentrations detected in the hair specimens ranged from 0·5 to 13·2 ng/mg of hair. It was also found that the use of shorter length segments (e.g. 1 cm length) gave a clearer, more detailed picture of the historic pattern of heroin use in the four subjects studied.
Real Time Validation of Paediatric Biochemical Reports Using the Valab-Biochem® System
Authors: Marchand Martine , Guibourdenche Jean , Saada Jacqueline , Le Men Hervé , Porquet Dominique , Demelier Jean-François
Published: February 2014

Validation of biochemical reports must be fast and clinically accurate to be of assistance to clinicians. Considerable skill is required to analyse the consistency of different data in the report and to consider influences on the data. When performed throughout the day, such analysis is time-consuming and uncertain. We therefore decided to use a computer-assisted validation system, Valab-Biochem®. Its decisions result from a decision tree based primarily on the intrinsic consistency of the data, validation ranges and patients' sex, age and hospital ward. Three hundred randomly chosen reports were simultaneously submitted to Valab-Biochem and to five biologists in order to analyse the computer's findings. The sensitivity of Valab-Biochem was 80% compared to biologists' consensus decision, which was taken as the gold standard. The specificity was 78%. This system provided autonomous assessment of the reports and could be used as an initial screen to assist biologists and focus attention on potentially inconsistent reports.
Two Years' Experience with an Enhanced Chemiluminescent Assay for Neonatal Blood Spot TSH
Authors: John Rhys , Henley Robert , Oversby Nicholas
Published: February 2014

We have developed a blood spot assay for thyroid stimulating hormone (TSH) based on the Amerlite TSH-30 serum assay for use in the Welsh neonatal hypothyroid screening programme. A total of 67 656 infants were screened in 1994 and 1995, and 28 cases of primary hypothyroidism were detected, giving a prevalence of one in 2416. The method is sensitive and rapid, results being available within 3 h of receipt of samples. The assay enables much faster detection of primary hypothyroidism than was previously possible, and therefore contributes to earlier treatment of affected infants.
A Semiautomated Alanine: Glyoxylate Aminotransferase Assay for the Tissue Diagnosis of Primary Hyperoxaluria Type 1
Authors: Rumsby G , Weir T , Samuell C T
Published: February 2014

We have developed a sensitive assay for the measurement of alanine:glyoxylate aminotransferase (EC 2.6.1.44) activity in human liver. The assay is partly automated, and takes into consideration the sensitivity of the reaction to pH and to glyoxylate concentration. It is less subject to interference from other enzymes utilizing glyoxylate and to chemical interference from glyoxylate itself and can therefore be used without correction for cross-over by glutamate:glyoxylate aminotransferase (EC 2.6.1.4). The assay allows clear discrimination between normal and affected livers and is sufficiently sensitive to measure enzyme activity in fetal liver samples. Enzyme activity ranged from 17·9 to 38·5 μmol/h/mg protein in control livers ( n = 9) and 0·8 to 9·5 μmol/h/mg protein in 30 of 39 hyperoxaluric patients studied. Normal alanine: glyoxylate aminotransferase activity (from 22·8 to 45·5 μmol/h/mg protein) allowed exclusion of primary hyperoxaluria type 1 in the other nine hyperoxaluric patients.
Clinical Significance of Urinary Human Tissue Non-Specific Alkaline Phosphatase (hTNAP) in Pre-Eclampsia and Eclampsia
Authors: Shaarawy Mohamed , Mallah Samira Youssef El , El-Yamani Azza Abd El-Monem
Published: February 2014

The aim of this work was to determine the levels of urinary human tissue non-specific alkaline phosphatase (hTNAP) in pre-eclampsia and eclampsia in order to assess renal tubular damage. Urine samples were collected from 26 mild pre-eclamptic, 26 severe pre-eclamptic, 20 eclamptic patients and 20 healthy pregnant women (controls) in their late third trimester. Urinary hTNAP/creatinine (hTNAP/cr) in severe pre-eclampsia and eclampsia were significantly higher than in controls. Urinary hTNAP/cr was increased in 23%, 77% and 90% of cases of mild pre-eclampsia, severe pre-eclampsia and eclampsia, respectively, indicating that the increase correlates with the severity of the disease. Marked elevation or urinary hTNAP/cr was also associated with bad fetal outcome. These results provide additional evidence for renal tubular damage in pre-eclampsia and eclampsia.
Enhanced Chemiluminescent Assay for Measuring the Total Antioxidant Capacity of Serum, Saliva and Crevicular Fluid
Authors: Chapple I L C , Mason G I , Garner I , Matthews J B , Thorpe G H , Maxwell S R J , Whitehead T P
Published: February 2014

This paper reports the development of an enhanced chemiluminescent (ECL) assay for measuring the total antioxidant (AO) capacity of serum, saliva and a fluid collectable from the gum margin called gingival crevicular fluid (GCF). The theory behind the assay is explained, and the optimum conditions for the assay, and for storage of reagents and clinical samples is described. Calibration lines were linear ( R≥0·99; P<0·0001) and the within batch coefficient of variations for a water soluble vitamin E analogue (Trolox), serum and saliva samples were <5%. In saliva and GCF, a characteristic AO response not seen in serum of the same patients, was identified. Total peripheral (serum) and local (saliva) AO capacities (μmol/L Trolox) were investigated in patients with ( n = 18) and without ( n = 16) adult periodontitis. Serum AO status did not differ between groups. Salivary total AO concentrations were lower in the periodontitis (P) group [175 (53)μmol/L] than in the nonperiodontitis (NP) group [254 (110)μmol/L1: P<0·01], as were saliva:serum AO ratio's [0·37 (0·11) versus 0·5 (0·18): P<0·01]. Periodontitis patients may have a reduced salivary AO concentration, which could result from, or predispose to, the damaging effects of reactive oxygen species (ROS). The potential for ROS production in the oral and periodontal environment may explain the presence of a specific antioxidant in oral fluids that is not detectable in serum. The ECL assay described provides a rapid, simple and reproducible method of measuring total antioxidant defence in small volumes of biological fluids.
Variation of the CGG Repeat in FMR-1 Gene in Normal and Fragile X Chinese Subjects
Authors: Chen T A , Lu X F , Che P K , Ho Walter K K
Published: February 2014

The fragile X syndrome is believed to be caused by an expansion of a CGG trinucleotide repeat segment in the FMR-1 gene on the fragile X site of the long arm of the X-chromosome. To understand the variation of the CGG repeat in the FMR-1 gene in southern Chinese from the Hong Kong and Guangzhou area, we undertook the present study. A total of 83 normal and three fragile X subjects were examined. In the normal group, 16 distinct alleles, ranging in size from 272 bp to 332 bp with 17 to 37 CGG repeats were detected. A repeat size of 29 was the most frequent. Compared with data collected in the USA, the repeat size observed in this population was somewhat smaller. Whether this discrepancy is due to ethnic difference remains to be determined. The three fragile X patients examined in this study did not have a greatly expanded CGG segment. One of them may be a mosaic with one full and one premutation allele. The other two patients, although having clinical and cytological features of fragile X syndrome, had a CGG repeat size within normal range. To explain this, we infer that the mutation in these patients may be caused by other mechanisms, such as other types of FMR-1 mutation or mutation in another site. It is possible that the expansion of the CGG repeats may not be as frequent a cause of fragile X syndrome in southern Chinese as in other ethnic groups.
A Non-Isotopic Method for Estimating 11β Hydroxysteroid Dehydrogenase Activity In Vivo
Authors: Bayly G R , Bartlett W A , Jones A F
Published: February 2014

11 β-hydroxysteroid dehydrogenase (11βHSD) has both dehydrogenase (11βDH) and reductase (11βR) activities, which catalyse the interconversion of Cortisol and cortisone, and prednisolone and prednisone. This enzyme confers specificity on the mineralocorticoid receptor by local oxidation of Cortisol to cortisone. Using radiolabeled Cortisol 11βHSD activity has been shown to be lower in some cases of essential hypertension. This study investigated a novel approach to estimating 11βHSD activity in vivo. Plasma steroid kinetics were investigated following oral hydrocortisone (a substrate for 11βDH) and prednisone (a substrate for 11βR) in five normotensive volunteers after dexamethasone suppression of endogenous steroid production. This approach was evaluated by inducing partial deficiency of 11βHSD in the volunteers who took liquorice (to inhibit 11βDH) and then carbenoxolone (to inhibit both 11βDH and 11βR). The ratio of Cortisol to prednisolone (formed from prednisone) provided a measure of the activity of both 11βDH and 11βR. At 75min after the steroid bolus the ratio increased from 1·1 (0·6–1·3) (median, range) under control conditions to 1·2 (0·8–1·7) after liquorice ( P = 0·01, n = 5), and 2·0 (1·3–5·9) after carbenoxolone ( P = 0·02, n = 5). It may therefore be applied to the measurement of 11βHSD activity in vivo in large numbers of hypertensive patients without the use of radioisotopes.
Radioimmunoassay for Serum Apolipoprotein D, an Atypical Apolipoprotein: Validation and Clinical Application
Authors: Osundeko Olusola , Tetlow Lesley , Bundred Nigel , Gowland Eric
Published: February 2014

Apolipoprotein D (apoD) is an atypical apolipoprotein in terms of its structure, synthesis and probable function. It is the most abundant protein in breast cyst fluids of patients suffering from macrocystic disease of the breast, a disease associated with an increased risk of developing breast cancer. We have developed and optimized a competitive radioimmunoassay for the measurement of apoD in human serum. The assay uses a solid phase separation method and with a 4h incubation period, it can be completed in a single working day. The within and between run coefficients of variation were <8·5% and <12·2%, respectively, and quantitative recovery of apoD was obtained over the range 250–5000 μg/L. There was no difference in the serum concentrations of apoD between female controls, patients with benign breast disease and early breast cancer. However, serum apoD was significantly lower in breast cancer patients with bone metastasis.
Serum S-100 Protein, Relationship to Clinical Outcome in Acute Stroke
Authors: Abraha Hagosa D , Butterworth Richard J , Bath Philip M W , Wassif Wassif S , Garthwaite John , Sherwood Roy A
Published: February 2014

The clinical significance of serum S-100 protein, a protein released by damaged brain tissue, was assessed in patients with acute ischaemic or haemorrhagic stroke and matched controls. Serum S-100 protein concentration was significantly elevated in patients with ischaemic stroke [median (SQR): 0·27 (0·09)μg/L, n = 68] and haemorrhagic stroke [0·43 (0·23)μg/L, n=13] compared to controls [0·11 (0·03)μg/L, n = 51, P<0·0001]. Although patients with haemorrhagic stroke had higher serum S-100 concentrations compared to patients with ischaemic stroke, this was not quite statistically significant. Serum S-100 concentrations were related to infarct size, large (total anterior circulation) infarcts concentrations having the highest [0·40 (0·22) μg/L], and small vessel (‘lacunar’) infarcts concentrations having the lowest [0·20 (0·06)μg/L, P<0·0005] concentrations. S-100 protein concentration was also significantly related to clinical outcome at three months measured using three disability and handicap scales ( n = 81): modified Barthel index ( rs=–0·285, P = 0·01), modified Rankin score ( rs = 0·313, P = 0·004) and Lindley score ( rs = 0·262, P = 0·018) with high values associated with poor clinical outcome. Similarly high values of serum S-100 protein were observed in patients who died or were discharged to an institution [median (SQR): 0·63 (0·29)μg/L and 0·37 (0·13)μg/L, respectively] compared to those who were discharged home [0·26 (0·11)μg/L, P = 0·13]. The present study suggests measurement of serum S-100 protein could be a useful prognostic marker of clinical outcome in acute stroke. Whether S-100 concentrations can be altered by therapeutic intervention in acute stroke remains to be elucidated. Indexing terms: acute stroke/serum S-100/Barthel index/Rankin scale.
Hyperproinsulinaemia in Acromegaly: Evidence for Abnormal Pancreatic β-Cell Function?
Authors: Gama R , Teale J D , Wright J , Ferns G , Marks V
Published: February 2014

We investigated whether pancreatic β-cell dysfunction has a role in the pathogenesis of glucose intolerance in acromegaly by comparing plasma intact proinsulin, immunoreactive insulin, C-peptide and glucose concentrations during a 75 g oral glucose load in six patients with active acromegaly and eight healthy volunteers. Only acromegalic patients with normal glucose tolerance were studied. Glucose concentrations were similar in acromegalic patients and controls. Acromegalic patients had higher fasting insulin ( P <0·005) and fasting C-peptide ( P <0·005) concentrations than controls. Although fasting proinsulin levels were higher in acromegalic patients than controls, this did not achieve statistical significance. Integrated insulin ( P <0·05), C-peptide ( P <0·05) and proinsulin ( P <0·005) concentrations were greater in acromegalic patients than control subjects. Integrated ( P <0·05) proinsulin: insulin molar ratios were higher in acromegalic patients than controls. Fasting and integrated insulin: C-peptide molar ratios were similar in acromegalic patients and controls. These results indicate that hyperproinsulinaemia contributes to the hyperinsulinaemia which characterizes active acromegaly. The disproportionate hyperproinsulinaemia in acromegaly suggests that prolonged and excessive growth hormone secretion may result in pancreatic β-cell dysfunction which may predispose acromegalic subjects to glucose intolerance.
Measurement of Plasma 1,25 Dihydroxyvitamin D Using a Novel Immunoextraction Technique and Immunoassay with Iodine Labelled Vitamin D Tracer
Authors: Fraser W D , Durham B H , Berry J L , Mawer E B
Published: February 2014

We evaluated a novel assay for the measurement of 1,25 dihydroxyvitamin D (1,25 (OH)2D). Immunoextraction of 1,25 (OH)2D is performed using a mini column containing a solid-phase monoclonal antibody followed by radioimmunoassay (RIA) using an 125I-labelled 1,25 (OH)2D derivative tracer and Sac-cell separation. The mean recovery of 1,25(OH)2D3 was 101%, linearity was excellent, inter- and intra-assay coefficients of variation were 9, 8 and 13% and 11, 10 and 14% at low, medium and high concentrations of 1,25(OH)2D3, respectively. The cross-reactivity of vitamin D metabolites was <0·0015% for 25-hydroxyvitamin D3, 24, 25 dihydroxyvitamin D3 and dihydrotachysterol and 0·54% for lα calcidol. 1,25 dihydroxyvitamin D2 cross-reactivity was 79%. The detection limit of the assay was 5pmol/L. Comparison with a commercial radio receptor assay (RRA) and an in-house RIA gave regression equations of y = 0·94x+11·8 ( r = 0·98) and y = 0·91x-1·7 ( r = 0.95), respectively, with no major discrepancies between the methods in all patient groups studied. Plasma concentrations of 1,25 (OH)2D obtained with the assay were as follows: normal, unsupplemented subjects: mean 88, range 48–155 pmol/L, n = 68, patients with chronic renal failure: mean 11, range 3–36 pmol/L, n = 27, primary hyperparathyroidism: mean 198, range 130–299 pmol/L, n = 23, Paget's disease: mean 92, range 42–149 pmol/L, n = 24, osteomalacia: mean 43, range 27–61 pmol/L, n = 9. A minimum sample volume of 300 μL is required, the hands-on time is significantly less than other commercial assays and the measuring procedure is gamma counting rather than scintillation counting. The assay offers several advantages over previous methods and should allow more laboratories to offer measurement of 1,25 (OH)2D as part of their repertoire.
Biochemical Effect of Antioxidants on Lipids and Liver Function in Experimentally-Induced Liver Damage
Authors: Halim Abdel-Baset , El-Ahmady Omar , Abdel-Galil Fathy , Darwish Amr , Hassab-Allah Samar , Hafez Yosri
Published: February 2014

Recent studies demonstrated the role of antioxidants in preventing organ damage caused by free radicals. The present study was conducted to find out the modulatory effect of some antioxidants on lipid patterns in experimentally-induced liver damage. Rats chronically intoxicated with carbon tetrachloride (CC14) were used as a model of liver injury terminating with fibrosis or cirrhosis. One hundred and sixty six albino rats were classified into five groups: one served as a control group; the second was subjected to oral administration of CC14 (200 μL/100 g body weight) twice a week; the other three groups, in addition to CC14, received oral doses of silymarin (30mg/kg), vitamin E (200 IU/kg) and vitamin C (50mg/kg) respectively. At the end of the experiment, the animals were killed, blood was collected and liver was taken for histopathological examination. Liver function tests, disturbed by CC14 were significantly modulated by antioxidants, and histopathological examination showed that antioxidants ameliorated the necrotic and fibrotic changes caused by CC14. Treatment with antioxidants was also shown to modulate the toxic effect of CC14 on the lipid profile and malondialdehyde content. Administration of antioxidants could play an important role in prophylaxis against lipid peroxidation and consequently liver fibrosis caused by free radicals.
Identification of Apo(a) Phenotypes in a Korean Population Using a Standardized Nomenclature System Based on the Number of Kringle IV Repeats
Authors: Min Won-Ki , Lee Jae Ok , Kim Chun Hee , Song Junghan , Kim Jin Q
Published: February 2014

We determined serum lipoprotein(a) [Lp(a)] concentrations and apolipoprotein(a) [apo(a)] phenotypes in 193 healthy Koreans. We analysed the apo(a) phenotypes by a simplified sodium dodecyl sulphate-polyacrylamide gel electrophoresis method and classified apo(a) isoforms objectively using an apo(a) phenotype standard with a known number of kringle IV repeats. The frequency distribution of Lp(a) levels showed marked positive skew with a mean of 0·143 g/L and a median of 0·052 g/L. Of the 193 subjects tested, no bands were detected in three, and single- and double-band phenotypes were observed in 103 and 87, respectively. Among the Koreans, the most frequent phenotype was S5(39·4%), followed by S4S5(17·1%), S5S5(14·0%), S4(11·4%), S3S5(5·2%), and the remaining phenotypes (13·0%). The calculated apo(a) allele frequencies were LpF, 0·003; LpS1, 0·013; LpS2, 0·010; LpS3 0·048; LpS4 0·198; LpS5, 0·563 and Lp0, 0·165. We found that the serum Lp(a) concentration in Koreans was similar to that of Caucasians, but the apo(a) allele size distribution was shifted toward higher molecular weights.
Screening for Down's Syndrome: The Effect of Test Date on the Detection Rate
Authors: Dunstan F D J , Nix A B J
Published: February 2014

Screening tests for Down's syndrome are carried out at different gestational ages. Because of fetal loss, crude estimates of their detection rates cannot be directly compared. We present methods for estimating the true detection rates along with their standard errors. This enables a proper statistical comparison of the true detection rates of tests carried out, for example, in different trimesters.
The Reproducibility and Usefulness of the Oral Glucose Tolerance Test in Screening for Diabetes and other Cardiovascular Risk Factors
Authors: Ko Gary T C , Chan Juliana C N , Woo Jean , Lau Edith , Yeung Vincent T F , Chow Chun-Chung , Cockram Clive S
Published: February 2014

We examined the reproducibility of oral glucose tolerance tests (OGTT) using the World Health Organization criterion in 212 Chinese subjects (male 149, female 63) who underwent two 75 g OGTTs within a 6-week period. The overall reproducibility was 65.6% (139/212) of which 74 subjects had normal glucose tolerance, 24 had diabetes and 41 had impaired glucose tolerance (IGT) on two occasions. The subjects were divided into three groups [group 1: normal OGTTs on both occasions ( n = 74); group 2: one abnormal OGTT (either diabetes or IGT ( n = 51); group 3: 2 abnormal OGTTs ( n = 87)]. Subjects in group 1 were younger, had lower blood pressure, body mass index (BMI), waist-to-hip ratio (WHR), fasting and 2 h plasma insulin levels, triglyceride, very — low density lipoprotein and apolipoprotein-B concentrations than both groups 2 and 3. Group 2 had similar characteristics as group 3 except for a lower glycated haemoglobin (HbA1c), fasting and 2 h plasma glucose during the two OGTTs. With receiver operating characteristic curve (ROC) analysis, a HbA1c. of 5.3% gave an optimal sensitivity of 70.7% and specificity of 74.3% to predict diabetes as defined by a 2h plasma glucose value ≥ 11.1 mmol/L in the first OGTT. Of the 212 subjects, 73 had HbA1c ≥ 5.3%. The reproducibility of OGTT was 56.2% for these 73 subjects. With ROC analysis, a BMI of 25 kg/m2 gave an optimal sensitivity of 53.7% and specificity of 56.7% to predict diabetes. For the 36 subjects with BMI ≥ 25 kg/m2, the reproducibility of OGTT was 58.3%. Similarly, for the 140 subjects with WHR ≥ 0.9, the reproducibility of OGTT was 57.9%. These findings confirmed the poor reproducibility of OGTT which was not improved even amongst subjects with high HbA1c, BMI or WHR. Furthermore, subjects with one abnormal OGTT, whether reproducible or not, had a higher cardiovascular risk profile compared to subjects who had two normal OGTTs.
Lipoprotein(a) Changes during and after Coronary Artery Bypass Grafting: An Epiphenomenon?
Authors: Cobbaert Christa , Louisa Annemarie , Struijk Lou , Demeyere Roland , Meyns Bart
Published: February 2014

The lipoprotein(a) (Lp(a)) time course during and after coronary artery bypass grafting was examined in 20 caucasoid patients, in relation to the time courses of serum cholesterol and serum triglycerides. Samples were taken at eight different time points. Baseline geometric means (SD) for Lp(a), cholesterol and triglycerides were 115 (336) mg/L, 5.73 (1.10) mmol/L and 1.73 (1.21) mmol/L, respectively. Up to 10 min after cardiopulmonary bypass (CPB) and after correction for haemodilution, no observable effect of CPB on serum concentrations of Lp(a) could be demonstrated, whereas serum concentrations of total cholesterol and triglycerides showed a progressive and significant decline. Ten minutes after stopping CPB geometric means for cholesterol and triglyceride were 3.90 (0.82) and 0.90 (0.58) mmol/L, respectively. At the third post-operative day geometric Lp(a) and cholesterol means decreased to 62 (90) mg/L and 2.97 (0.84) mmol/L, respectively, while triglycerides went up. It is concluded that Lp(a) levels remain constant during CPB, but mimic total cholesterol changes in the post-CABG period.
Kinetic Analysis and Tissue Distribution of Human D-Glycerate Dehydrogenase/Glyoxylate Reductase and its Relevance to the Diagnosis of Primary Hyperoxaluria Type 2
Authors: Giafi C F , Rumsby G
Published: February 2014

The enzyme D-glycerate dehydrogenase (D-GDH; EC 1.1.1.29), which is also believed to have glyoxylate reductase (GR; EC 1.1.1.26/79) activity, plays a role in serine catabolism and glyoxylate metabolism and deficiency of this enzyme is believed to be the cause of primary hyperoxaluria type 2 (PH2).

The pH optima and kinetic parameters of D-GDH and GR in human liver have been determined and assays developed for their measurement. Maximal activities were observed at pH 6.0, 8.0 and 7.6 for the D-GDH forward, D-GDH reverse and GR reactions, respectively. The apparent Km values for the substrates in these reactions were as follows: D-GDH forward reaction, 0.5 mmol/L hydroxypyruvate and 0.08 mmol/L NADPH; D-GDH reverse reaction, 20 mmol/L D-glycerate and 0.03 mmol/L NADP and for the GR reaction 1.25 mmol/L glyoxylate and 0.33 mmol/L NADPH. The forward D-GDH and GR assays were adopted for routine use, the low activity of the reverse D-GDH reaction being of little use for routine analyses.

D-GDH and GR activity in 13 normal livers ranged from 350–940 nmol per min per mg protein (median 547) and 129–209 nmol per min per mg protein (median 145), respectively. D-GDH activity in kidney, lymphocytes and fibroblasts fell within the range of values seen in the liver but GR activity was approximately 30% in the kidney and barely detectable in lymphocytes and fibroblasts. Analysis of liver and lymphocyte samples from patients with PH2 showed that GR activity was either very low or undetectable while D-GDH activity was reduced in liver but within the normal range in lymphocytes. These results suggest that there is more than one enzyme with D-GDH activity in human tissues but only one of these has significant GR activity. We conclude that a definitive diagnosis of PH2 requires measurement of GR and D-GDH in a liver biopsy.
Alkaline Phosphatase Activity Measurement in the UK by AMP-Buffered Methods: An Appraisal of Current Practice
Authors: Lamb E J , Browne M , John W G , Price C P
Published: February 2014

Most UK clinical laboratories use alkaline phosphatase (ALP) methods similar to that proposed by the International Federation of Clinical Chemistry (IFCC), based on the use of 2-amino-2-methyl-l-propanol (AMP) buffer. We present evidence of significant differences in results produced by apparently similar commercial ALP methods using an AMP buffer. We compared Bayer DAX, Dade Dimension and Boehringer Mannheim Hitachi 717 methods. Boehringer and Dade results were higher than Bayer results (Bland and Altman analysis, log transformed data): Boehringer (+ 23.0%, limits of agreement 1.16–1.31 times Bayer); Dade (+ 21.9%, limits of agreement 1.13–1.32 times Bayer). Biases were predominantly due to differences in reagents rather than analyser characteristics. Compared to a reagent system prepared exactly as described by the IFCC, Bayer was sub-optimal and Dade and Boehringer methods produced results higher than the IFCC method. Reference ranges and results on patients' samples by the various methods showed large differences but no clinically significant difference was observed in external quality assessment schemes either between Bayer and Boehringer or against method means. Apparently similar methods produce different results in patients' sera: external quality assessment schemes are not useful in highlighting these differences.
Serum Sialic Acid, a Reputed Cardiovascular Risk Factor, is Elevated in South Asian Men Compared to European Men
Authors: Crook M , Kerai P , Andrews V , Lumb P , Swaminathan R
Published: February 2014

Serum total sialic acid (TSA) has recently been reported as a cardiovascular risk factor, but whether there are racial differences is not known. One hundred and twenty-four healthy young subjects (62 women and 62 men) were studied. Their age was 20.7 [0.9] years and they were matched for body mass index (BMI). Sixty-eight were of South Asian origin (37 women and 31 men) and 56 (25 women and 31 men) were European.

Mean (SD) serum TSA was significantly higher in the South Asian men than the age-matched European men (74.3 [12.3]mg/dL versus 68.2 [13.0]mg/dL, P = 0.0198). In addition, serum TSA was significantly higher in South Asian women compared with European men (71.6 [8.9]mg/dL versus 68.2 [13.0]mg/dL, P = 0.0352). Finally, serum TSA was significantly higher in European women compared with European men (76.0 [13.1]mg/dL versus 69.2 [130]mg/dL, P = 0008).

We conclude that serum TSA may be worth measuring in different racial groups and also may be useful to assess individuals at risk of cardiovascular disease. Large prospective studies may help to explain why serum TSA is a reputed cardiovascular risk factor and shows racial differences.