bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of a Commercial Enzymic Kit for Urinary Oxalate Analysis with a High Performance Liquid Chromatographic Method
Authors: Starkey Bryan J , Fry Ian D R 
Published: February 2014

A new commercial enzymic kit for urinary oxalate determination has been adapted for use on a centrifugal analyser. It has been evaluated and compared with an established high performance liquid chromatographic (HPLC) procedure developed in our laboratory. Mean recovery of oxalate from urine samples augmented with oxalic acid exceeded 97% by both methods. The precision of the HPLC method was superior to that of the enzymic kit but both methods gave between batch precision values better than CV 12% at low (less than 100μmol/L) oxalate concentrations and better than CV 7% at higher concentrations (greater than 270μmol/L) Urinary oxalate values obtained with the new enzymic procedure correlated more closely with HPLC values ( r = 0·84) than did values previously obtained using the forerunner of the kit ( r = 0·62) which was known to be susceptible to ascorbate interference. No significant interference from ascorbic acid or from high urinary calcium concentrations could be demonstrated using either the improved kit or the HPLC procedure. Its easy adaptation to automated analysers available in most laboratories, coupled to its acceptable analytical performance render the enzymic kit a reasonable alternative to HPLC or other more complex procedures for urinary oxalate analysis.
Improved Formulae for the Judgement of Intrathecal Produced IgA and IgM in the Presence of Blood CSF Barrier Damage
Authors: Öhman Sten , Ernerudh Jan , Forsberg Pia , von Schenck Henning , Vrethem Magnus 
Published: February 2014

In order to discriminate between transsudated and intrathecally produced IgA and IgM in patients with blood cerebrospinal fluid (CSF) barrier (BCB) damage, we developed extended indices (IgA-EI and IgM-EI) for these immunoglobulins according to the general formula for extended index of a component X in CSF: where a is a parameter specific for X. For IgA parameter a was found to be 1·15 and for IgM 1·9. A preliminary evaluation of IgA-EI and IgM-EI indicated lower false positive rates as compared to CSF IgA and IgM concentrations as well as ‘conventional’ IgA and IgM indices in cases with BCB damage, and essentially the same rates as for the hyperbolic formulae of Reiber and Felgenhauer. The importance of reliable sampling and analytical technique for IgM in CSF is discussed.
Differences between the Sugar Moieties of Liver- and Bone-Type Alkaline Phosphatases: A Re-Evaluation
Authors: Miura Masakazu , Sakagishi Yoshikatsu , Hata Keishi , Komoda Tsugikazu 
Published: February 2014

We re-evaluated the differences between the sugar moieties of liver and bone alkaline phosphatases (ALPs). Sialic acid was added to ALP sugar moieties by α2,3- or 2,6-sialyltransferase treatment of the asialo-form ALP (neuraminidase-treated ALP). Asialo-bone ALP was converted to a liver-like ALP by the 2,6-sialyltransferase treatment. The resulting liver-like ALP was less susceptible to neuraminidase than non-treated bone ALP, but was still labile to heat exposure at 56°C like non-treated bone ALP. However, after the O-linked sugar moiety had been released by additional treatment with O-glycanase the liver-like ALP became more heat stable at 56°C, like non-treated liver ALP. Non-treated liver ALP reacted specifically with anti-liver ALP monoclonal antibody, and non-treated bone ALP reacted with both anti-liver and anti-bone ALP antibodies. The asialo-bone ALP still reacted with anti-bone ALP antibody, whereas the asialo-form liver ALP showed little, if any, reaction with anti-liver and anti-bone ALP antibodies. Neuraminidase and O-glycanase-treated bone ALP reacted less with anti-bone ALP antibody. After O-glycanase treatment, bone ALP molecules deprived of an O-linked sugar moiety had a molecular size and heat stability similar to liver ALP. The difference between liver and bone ALP molecules may be due not only to their manner of sialic acid linkage but also to the attachment of the O-linked sugar moiety.
A Novel Method for Concentrating Urinary Type IV Collagen Based on Precipitation with Polyethylene Glycol: Application to Its Measurement by Enzyme Immunoassay
Authors: Banu Nazifa , Hara Hitoshi , Kataoka Shinkuro , Egusa Genshi , Yamakido Michio 
Published: February 2014

We investigated the efficacy of polyethylene glycol (PEG) for effective and reproducible concentration of urinary type IV collagen prior to measurement by enzyme immunoassay (EIA). Human placental type IV collagen at low concentrations (5 and 10μg/L) and urinary type IV collagen were readily precipitated by PEG-4000 added at a concentration of about 150 g/L in the presence of 0·5 g/L γ-globulin. Type IV collagen measurement by EIA from PEG-concentrated urine samples showed complete recovery and good reproducibility. Analysis of size distribution by Sephacryl S-300HR gel chromatography and Western blotting following polyacrylamide gel electrophoresis confirmed that type IV collagen in PEG-concentrated urine samples was of high molecular weight comparable to that of human placental type IV collagen. After PEG concentration, type IV collagen was detectable by EIA even in the urine of healthy subjects. Significantly higher concentrations of urinary type IV collagen were found in 30 diabetic patients with nephropathy than in 20 healthy subjects [99·5 (8·9)μg/L, mean (SEM) versus 21·4 (2·6)μg/L, P<0·0001]. Thus, urinary type IV collagen can be measured effectively by EIA following concentration with PEG. This method has potential for the assessment of the progression of diabetic nephropathy.
Evaluation of Human IgG Subclass Assays on Beckman Array
Authors: Pressac M , Allouche F , Circaud R , Aymard P 
Published: February 2014

Automated immunonephelometric assays were developed to measure human IgG subclasses in serum, on the Beckman Array Protein System (APSR), with sheep antihuman IgG subclass antisera. The interassay imprecision was judged to be satisfactory in each case (CV: IgG,: 2·3%; IgG2: 2·9%; IgG3: 4·0% and IgG4 5·4%). The standard curves were found to be linear in the ranges 1·5–30·0 g/L for IgG1, 1·5–15·0 g/L for IgG2, 0·1–1·0 g/L for IgG3 and 0·1–1·0 g/L for IgG4. The lower limit for quantification of the immunonephelometric assays was 0·50 g/L for IgG1, 0·04 g/L for IgG2, 0·06 g/L for IgG3 and 0·03 g/L for IgG4. We found no antigen excess to at least 60·0 g/L for IgG, and IgG2, 3·5 g/L for IgG3 and 2·0 g/L for IgG4. Nephelometric results correlated with those of radial immunodiffusion (r = 0·96 for IgG1, r = 0·93 for IgG2, r = 0·90 for IgG3 and r = 0·96 for IgG4). The reaction monitored by the Beckman Array Protein System is easy to perform, rapid and precise. The performance makes the immunonephelometric method suitable for the determination of IgG subclass concentrations in routine analysis.
Cerebrospinal Fluid Interleukin-6 and Its Diagnostic Value in the Investigation of Meningitis
Authors: Hashim I A , Walsh A , Hart C A , Shenkin A 
Published: February 2014

We examined the measurement and the diagnostic value of cerebrospinal fluid interleukin-6 (CSF IL-6) in meningitis. The cytokine was measured by bioassay (B9 hybridoma cell line) and by immunoassay (in-house radioimmunoassay). We compared the diagnostic value of CSF IL-6 determination with that of other biochemical markers of meningitis. Although there was significant correlation between bioactive and immunoactive IL-6 ( r = 0·724, P < 0·001), results were frequently different with biological/immunological ratios ranging from 0·2 to 24·3 (mean 4·6). Gel permeation chromatography suggested that the discrepancy in biological and immunological activities was not due to molecular heterogeneity, but may be explained by the presence of a synergistic factor. Interleukin-6 concentration was markedly elevated in CSF from most patients with bacterial meningitis compared to patients with viral meningitis and those without evidence of infection. However, low IL-6 levels by radioimmunoassay did not exclude bacterial meningitis (sensitivity 86%). CSF total protein and CSF glucose were significantly different between all three groups, but there was no significant difference in lactate concentration between virally infected and normal CSF, both of which had lower lactate concentrations than those in bacterial infection. CSF IL-6 measurement had greater sensitivity, specificity and predictive value than these other biochemical markers, and hence a rapid assay for IL-6 in CSF may contribute to the early diagnosis of bacterial infection.
The Effect of Anticoagulant Choice on Apparent Total Antioxidant Capacity using Three Different Methods
Authors: Goode Helen F , Richardson Norma , Myers David S , Howdle Peter D , Walker Barry E , Webster Nigel R 
Published: February 2014

We assessed total antioxidant capacity using three different methods, in plasma samples treated with either EDTA or heparin as anticoagulant, from 26 healthy subjects. Total antioxidant capacity was determined using an oxygen electrode (as the total peroxyl radical-trapping antioxidant parameter), by enhanced chemiluminescence, and by measurement of the antioxidant-mediated quenching of the absorbance of a radical cation. The choice of anticoagulant had a profound effect on antioxidant capacity with heparinized plasma giving consistently higher values than plasma anticoagulated with EDTA. Using the oxygen electrode the mean value was 786·5 ± 171·5 μmol/L (heparin) compared to 681·4 ± 160·4 μmol/L (EDTA, P < 0·01). The chemiluminescence technique gave a mean antioxidant capacity of 915·6 ± 214·1 μmol/L in heparin samples and 714·4 ± 195·4 μmol/L in EDTA samples ( P < 0·0001). The absorbance quenching technique gave a mean value of 867·0 ± 199·2 μmol/L (heparin) and 675·5 ± 245·4 μmol/L (EDTA, P < 0·001). All methods tested showed comparable results for EDTA plasma, but the chemiluminescence technique gave higher apparent antioxidant capacity than either of the other two techniques when heparin plasma was used. We suggest that either heparin is interacting to enhance antioxidant protection perhaps through release of superoxide dismutase, or the chelation of metal ions by EDTA is limiting the activity of antioxidant metalloenzymes. Consistency in the choice of anticoagulant is clearly extremely important.
High-Performance Liquid Chromatographic Determination of Pyridinium Crosslinks in Serum, Urine and Dialysate of Patients in Chronic Renal Failure
Authors: Ibrahim Suhaila , Mojiminiyi Segun , Barron Jeffrey L 
Published: February 2014

This study describes an isocratic reversed phase high-performance liquid chromatographic method for the analysis of pyridinium crosslinks in serum, urine and dialysates obtained from patients with chronic renal failure on haemodialysis. The mean (SD) urine pyridinoline (PYD) and deoxypyridinoline (DPD) to creatinine (Cr) ratio in 19 healthy volunteers was 28 · 9 (6 · 3) and 9 · 1 (3 · 6) μmol/mol, respectively. In the 22 patients the PYD/Cr and DPD/Cr ratio was 244·6 (436·5) and 66·5 (116·8)/μmol/mol, respectively. The mean serum PYD concentration in 29 patients of 268 · 5 (334 · 4) nmol/L was significantly higher than that of 5 · 9 (1 · 5) nmol/L found in normal volunteers: the mean DPD concentration was 82·9 (93·7) nmol/L in the patients but was undetectable in the serum from the normal volunteers. The concentration of crosslinks in pre-dialysis serum samples was higher than those found post-dialysis reflecting a significant removal of the crosslinks during dialysis. The assay of pyridinium crosslinks in serum, urine and dialyses fluid could potentially provide evidence of bone collagen turnover in patients in renal failure. Their measurement in serum and dialysate could be particularly useful in anuric patients.
Adjustment of Serum Total Calcium for Albumin Concentration: Effects of Non-Linearity and of Regression Differences between Laboratories
Authors: Barth J H , Fiddy J B , Payne R B 
Published: February 2014

It has been reported that the relationship between serum total calcium and albumin concentrations in hospital patients deviates from linearity at low albumin concentrations. We searched a large laboratory computer data base for adult patients with discretionary requests for serum calcium analysis but with no other data suggestive of disturbances of calcium homeostasis, and collected a minimum of 100 calcium values at each of a wide range of albumin concentrations. We confirmed the earlier observation, but found that the use of a single regression to derive an adjustment of total calcium for albumin gave only small differences of no clinical significance. To investigate whether equations to adjust total calcium for albumin can be transferred between laboratories, three laboratory computers were searched for calcium requests from patients likely to have a low prevalence of calcium disturbances. The regressions of total calcium on albumin differed significantly between laboratories, but within each laboratory gave adjusted calcium values identical with those in health. Although the errors resulting from applying an equation from one laboratory to another were small and unlikely to be of major clinical significance, we recommend that where possible laboratories should derive adjustment equations from their own data.
Evaluation of a New, Rapid and Automated Immunochemiluminometric Assay for the Measurement of Serum Intact Parathyroid Hormone
Authors: Michelangeli Valdo P , Heyma Paula , Colman Peter G , Ebeling Peter R 
Published: February 2014

The Immulite parathyroid hormone (PTH) immunochemiluminometric assay (ICMA) was evaluated by measuring serum PTH concentrations in 134 volunteers and 251 patients with various diseases affecting bone and mineral metabolism and comparing with those measured by the Nichols Allegro immunoradiometric (IRMA) assay. Although the assays were highly correlated ( r=0·99, P<0·0001), there were discrepancies at lower PTH concentrations which may be explained by the lower limit of detection of the ICMA assay. The anti-coagulants EDTA and heparin appeared to have significant effects on PTH measurement particularly at lower concentrations. Sera assayed by ICMA diluted out more uniformly than in the IRMA and there was no cross reactivity with parathyroid hormone-related peptide in either the IRMA or ICMA. Delays of up to 8 h in specimen handling did not appear to affect PTH measurements. The enhanced sensitivity of the Immulite ICMA intact PTH assay confers an advantage in the diagnosis of both hyper- and hypocalcaemia, while the shorter incubation times, automation and lack of radioactivity are important practical advantages.
Oxidative Stress of Vanadium-Mediated Oxygen Free Radical Generation Stimulated by Aluminium on Human Erythrocytes
Authors: Abou-Seif M A M 
Published: February 2014

It has been suggested that aluminium stimulates vanadium-mediated superoxide radical generation. The oxidative stress of generated superoxide radicals on antioxidant enzyme activity, oxidation of NADH and NADPH, membrane lipid peroxidation and osmotic fragility in human red blood cells (RBC) was investigated. RBC were incubated with varying concentrations of vanadium and aluminium ions at 37°C for 2 h. RBC incubated with vanadium ions showed significantly increased superoxide dismutase and catalase activities, and oxidized NADH and NADPH concentrations compared with control RBC preparations. Erythrocyte lipid peroxidation was assessed by measuring thiobarbituric acid reactivity. RBC incubated with elevated levels of vanadium showed significantly increased membrane lipid peroxidation when compared with control RBC; it increased further on addition of aluminium. A significant positive correlation was observed between the extent of vanadium induced membrane lipid peroxidation and the osmotic fragility of treated RBC. In the presence of vanadium, aluminium stimulates superoxide dismutase and catalase activities, NADH and NADPH oxidation and membrane lipid peroxidation, as well as increasing osmotic fragility of human erythrocytes. The stimulatory effect of aluminium was dependent on concentration. These results may have implications for the mechanism of toxicity of aluminium and vanadium in haemodialysis patients.
Glucose Interference in the Pancreolauryl Test
Authors: Trewick A L 
Published: February 2014

The influence of the glucose concentration in urines being assayed as part of a pancreolauryl test was investigated. Paired patient urines ( n = 5) were assayed at 60° and 70°C, before and after spiking to 5% glucose. The influence of assay temperature alone was assessed using glucose-free paired patient urines ( n = 10). Aqueous glucose solutions and spiked (5% glucose) normal random urines ( n = 5) were assayed to assess the effect of glucose concentration alone. There was no difference in T/K ratios for glucose-free patient samples at 60°, 70° and 80°C. After spiking with glucose T/K ratios were significantly different when assayed at 70°C, but not when assayed at 60°C. Aqueous glucose solutions ≥ 0.6% produced a pigment at temperatures ≥ 65°C which absorbed at the λmax of fluorescein. Glucose was found to interfere in the pancreolauryl test. Caution should be exercised when interpreting results from glucosuric samples.
Isolation and Properties of a Novel Phospholipase a from Rat Brain That Hydrolyses Fatty Acids at sn-1 and sn-2 Positions
Authors: Yoshida Hiroshi , Tsujishita Yosuke , Hullin Françoise , Yoshida Kimihisa , Nakamura Shun-Ichi , Kikkawa Ushio , Asaoka Yoshinori 
Published: February 2014

A Ca2+-independent phospholipase A that releases various fatty acids from sn-1 and sn-2 positions was partially purified from rat brain soluble fraction. The enzyme showed an approximate molecular mass of 300 kDa on gel filtration column chromatography. Its enzymatic properties are distinct from those of well characterized phospholipase A2 enzymes; by using a series of synthetic phosphatidylcholines, the enzyme cleaved oleic, linoleic, and arachidonic acids like phospholipase A2, and released palmitic and stearic acids like phospholipase A1. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid were hydrolysed with almost equal efficiencies by this enzyme. These results indicate that the enzyme isolated is a novel Ca2+ -independent intracellular phospholipase A that might be responsible for production of various fatty acids from membrane phospholipids.
Cardiac Troponins in Patients with Renal Dysfunction
Authors: Collinson P O , Hadcocks L , Foo Y , Rosalki S B , Stubbs P J , Morgan S H , O'Donnell J 
Published: February 2014

Cardiac troponin T (cTnT) and cardiac troponin I (cTnI) were measured in 198 patients with renal dysfunction [132 men: median (range) age 66·1 (8·2-90·3) years]. cTnT was measured by two methods: ELISA and Enzymun (Boehringer Mannheim UK, Lewes, UK), both with a detection limit of 0·05 μg/L in 179 and 78 patients, respectively. cTnI was measured in 80 patients by the OPUS plus and OPUS Magnum systems (Dade-Behring, Milton Keynes, UK) with a detection limit of 0·5 μg/L. Patients were classified as having chronic renal impairment (CRI), chronic renal failure (CRF), acute renal failure including those with multiple organ failure on renal replacement therapy (ARF), and patients with chronic renal failure treated with haemodialysis (HD). Cardiac troponins were detectable in the serum of patients with renal dysfunction. cTnT was detectable in 113/179 (63·1%) and 33/78 (42·3%) by the ELISA and Enzymun methods respectively. cTnI was detectable in 17/80 (21·3%). cTnT (ELISA and Enzymun methods) and cTnI were detectable with increased frequency in the CRF, HD and ARF patient groups compared with the CRI group. Cardiac troponin concentrations did not correlate with serum creatine kinase (CK) activity, CK-MB, or urea or creatinine levels. Serial cardiac troponin measurements may be required to confirm or exclude a diagnosis of acute coronary syndromes in patients with renal dysfunction.
Dietary Treatment of Hypercholesterolaemia: Lack of Relationship between Individual Response and Genetic Variation at the Lipase Loci
Authors: Chamberlain John C , Hill Diane , Shenkin Alan 
Published: February 2014

The individual benefits of dietary therapy for hyperlipidaemia are known to be unpredictable. Variants at the lipoprotein lipase gene have been shown to associate with atherogenic lipoprotein phenotypes and the delayed clearance of triglyceride-rich lipoproteins. Together with variants of the closely homologous hepatic lipase gene, these may influence the extent of amelioration of plasma lipoprotein concentrations seen in dyslipidaemic patients treated with a low saturates/low cholesterol diet. We correlated the lipid changes seen following an 8-week diet in 83 subjects with primary hypercholesterolaemia (fasting plasma cholesterol >6·5mmol/L) with alleles of three restriction polymorphisms (LPL-Hind III and Pvu II; HL-Msp I). Although dietary changes produced a significant improvement in fasting lipids [total cholesterol falling by 5·2% (range −27·9% to +24·3%) and low-density lipoprotein cholesterol reduced by 6·0% (−30·5% to +29·3%)], no significant difference in response between different genotypes could be detected.
Review of Investigation and Management of Severe Hyponatremia in a Hospital Population
Authors: Crook M A , Velauthar U , Moran L , Griffiths W 
Published: February 2014

The purpose of this study was to assess retrospectively the prevalence of severe hyponatremia in a hospital population and its laboratory investigation, treatment and clinical outcome. Over a 6-month period 47 patients (27 women and 20 men) were found to have a plasma sodium concentration of ≤ 120 mmol/L (this number made up less than 0·17% of all plasma sodium requests over that time period). The mean patient age was 75±16 years and the average hospital stay was 37±45 days (1–179 days). Patient mortality was 51% (women 57% and men 43%). The mean initial plasma sodium concentration was 116±4·5 mmol/L, rising after therapeutic intervention to a mean of 130±4·2 mmol/L. The mean plasma sodium correction rate was 4·7±4·3 mmol/L/24 h (0·9–17·5 range). Twelve per cent of the patients had their plasma sodium raised at a rate of greater than 10 mmol/L/24h after their initial presentation. Two patients may have had symptoms and signs suggestive of cerebral oedema/cortical dysfunction: in one patient the sodium concentration was raised at a rate of 9·5 mmol/L/24 h and in the other at 12·0 mmol/L/24h. Sixty-one per cent of the patients had a chest infection, 44% were on diuretics, 28% had congestive cardiac failure, 28% were post-operative (9% orthopaedic procedures), 19% had carcinoma and 9% were on a selective serotonin re-uptake inhibitor. Regarding laboratory investigations, 56% had liver function tests, 41% had thyroid function tests, 36% had plasma osmolality determination, 36% had urinary electrolytes including urinary osmolality and < 2% had tests to exclude hypoadrenalism.