bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous quantitation of homocysteine, cysteine and methionine in plasma and urine by liquid chromatography-tandem mass spectrometry
Authors: Weaving G , Rocks B F , Iversen S A , Titheradge M A 
Published: November 2006

Background: A method utilizing liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) has been developed and evaluated for the determination of total homocysteine, cysteine and methionine in plasma and urine. The simultaneous measurement of homocysteine and methionine concentrations may help explain the underlying mechanism responsible for hyperhomo-cysteinaemia. Methods: Samples were prepared by simple protein precipitation after reduction of disulphides by dithiothreitol. Reduced analyte signal caused by ionization suppression effects, seen with plasma samples, was compensated for with matrix-matched standards, and the use of isotopically labelled internal standards. Recovery for each analyte was better than 94%. Results: Concentrations of plasma homocysteine determined by LC-MS/MS were compared with those obtained by two automated commercially available FDA-approved procedures: (i) high-performance liquid chromatography (HPLC) with pre-column derivatization and fluorescence detection and (ii) by fluorescence polarization immunoassay (FPIA). Agreement with the LC-MS/MS method is given by the Deming regression equations LC-MS/MS = 1.062 HPLC-0.01 and LC-MS/MS = 1.104 FPIA-0.43. Conclusion: Low reagent costs together with the relative simplicity of sample preparation make the LC-MS/MS method well suited, not only for research work but also in those laboratories with a tandem mass spectrometer, for the measurement of routine clinical samples.
Vitamin D concentrations in an UK inner-city multicultural outpatient population
Authors: Ford Loretta , Graham Valerie , Wall Alan , Berg Jonathan 
Published: November 2006

Background: Vitamin D deficiency is still thought to be widespread in the UK and in recent years the number of cases of rickets reported in children has increased. In this study, the distribution of vitamin D and the prevalence of vitamin D deficiency have been determined for a multi-ethnic population from the inner-city area of Birmingham, UK, where a vitamin D testing service has been readily available for over 10 years. Methods: Serum 25-hydroxyvitamin D concentration was determined using an automated platform (Nichol's Advantage Speciality System) for 830 outpatient samples collected randomly at the end of summer (September). Results: In our total study population, prevalence of vitamin D deficiency, defined as a 25-hydroxyvitamin D concentration < 10 μg/L, was high (24%): one in eight Caucasians, one in four Black Afro-Caribbeans and one in three Asians were found to be deficient. Levels of deficiency were much higher in Asian women, with almost one in two individuals (43%) found to have a vitamin D level below 10 μg/L. Conclusion: Our study has shown that widespread vitamin D deficiency in a UK inner-city population remains an issue. In concordance with other studies, we found a high prevalence of vitamin D deficiency in Afro-Caribbean and Asians, and, in particular, women. It is clear that more routine screening of vitamin D is needed.
Serum calcium, urine calcium and polymorphisms of the calcium sensing receptor gene
Authors: Kelly Claire , Gunn Ian R , Gaffney Dairena , Devgun Manjit S 
Published: November 2006

Background: Recent studies have suggested a correlation between the A986S polymorphism of the calcium sensing receptor (CASR), and serum total and ionized calcium. This study aimed to assess the prevalence of three CASR polymorphisms in a West of Scotland population and relate genotype to serum and urine calcium levels. Methods: Fasting blood and urine samples were obtained from 121 healthy male and female volunteers aged 20-60 years. Volunteers were genotyped for the A986S, Q1011E and R990G polymorphisms using allele-specific amplification and amplification-created restriction site techniques. Total calcium, ionized calcium and urine calcium excretion were measured using automated clinical chemistry analysers. Results: Genotype frequencies for the A986S polymorphism were: AA, 74.4%; AS, 24.8%; SS, 0.8%. There was a small but statistically significant ( P < 0.01) increase in ionized calcium concentration in AS individuals compared with the wild type (1.22 versus 1.20 mmol/L). No statistical difference was detected in serum total calcium or parameters of urine calcium excretion. Genotype frequencies for the remaining polymorphisms were: RR, 82.6%; RG, 16.5%; GG, 0.8% and QQ, 93.4%; QE, 6.6%; EE, 0%. Biochemical parameters in these individuals were not statistically different from the wild type. Conclusion: The increase in serum ionized calcium in the AS group was small and, therefore, unlikely to be of clinical significance.
Effects of storage at -20°C on ischaemia-modified albumin results
Authors: Beetham R , Monk C , Keating L , Benger J R , Kendall J 
Published: November 2006

Background: Ischaemia-modified albumin (IMA) is being studied as a new marker for reversible ischaemia in patients presenting with possible cardiac chest pain. The conditions under which samples are stored prior to analysis may be critical in influencing the analytical result and hence the cut-off used in any particular study. Methods: Sixty-eight samples taken during a study assessing the performance of IMA for risk stratification in patients presenting with possible cardiac chest pain were analysed both within 2.5 h of collection and after periods of storage at -20°C. Results: Samples stored at -20°C yielded IMA values on average 3 units higher than those analysed within 2.5 h (mean 90.5 vs. 87.5; P < 0.00001). A Bland-Altman plot showed that the difference was not concentration dependent. Conclusions: These results indicate that decision cut-offs will be influenced by conditions of sample storage prior to IMA analysis, and that these should be stated in detail for each study.
Effect of variability in assay bias and imprecision on external quality assessment bias and imprecision measures
Authors: Hawkins Robert C 
Published: November 2006

Background: External quality assessment/proficiency testing programmes that report consensus means and coefficients of variations (CVs) are a potential source of information on assay bias and imprecision. This study examined the effect of variability in assay bias and imprecision on consensus means and CVs, using a computerized spreadsheet model. Methods: A model with varying assay bias (mean and standard deviation) and assay imprecision (mean and standard deviation) was developed using a MS Excel 2003 spreadsheet with a macro to generate pseudo-random numbers from a Gaussian distribution. The means, standard deviations and CVs of these data points were considered to simulate the consensus measures reported in external quality assessment testing programmes. Results: The simulated consensus CV was very sensitive to increases in assay bias variability, with greater effects at low levels of mean assay imprecision. Changes in assay imprecision variability had a much smaller effect on the simulated consensus CV, while the simulated consensus mean was relatively insensitive to any change in the other variables. Conclusion: Consensus imprecision measures from external quality assessment programmes are unreliable measures of assay imprecision. Consensus means are relatively unaffected by variability in assay bias and imprecision, and can be used as reliable measures of assay bias from a statistical standpoint.
Cellular content in plasma of Becton-Dickinson lithium-heparin tubes: cause of unreliable results in the IFCC-recommended lactate dehydrogenase method
Authors: Bakker Andries J , Bakker Anneke , Renting-Wiering Hennie 
Published: November 2006

Background: Measurement of lactate dehydrogenase (LDH) with the International Federation of Clinical Chemistry (IFCC)-recommended method in plasma was reported unreliable with primary evacuated lithium-heparin tubes from Becton-Dickinson, despite adequate removal of platelets from the plasma by optimized sample preparation. In this study, the composition of the top layer of the heparin plasma was investigated in relation to these duplicate errors. Method: Microscopic evaluation of cytospin preparations of the top layer of the plasma was compared with the difference between duplicates in the IFCC-recommended LDH assay using a Hitachi 911 analyser. Results: Duplicate errors could not be explained by the presence of one of the individual cell types. In 16 samples with cellular aggregates absent, three did show duplicate errors; all three had a moderate amount of red blood cells present. Conclusion: The presence of cellular aggregates in the top layer of the plasma was the main determinant for the occurrence of the high frequency of duplicate errors in the IFCC-recommended LDH method.
The Human Tissue Act: implications for clinical biochemistry
Authors: Laker M F 
Published: November 2006

The Human Tissue Act sets out a new legal framework for the use and retention of tissues from living persons as well as the removal, retention and use of tissue and organs from the deceased. The Human Tissue Authority (HTA) has been established as the regulatory body in relation to the Act and also to give advice and guidance initially through the publication of Codes of Practice. The HTA will also license activities within the remit of the Act and will inspect to ensure compliance with the Act and licence conditions. The Act establishes consent as the essential requirement for the lawful retention and use of tissues and organs; failure to comply could result in penalties that include a custodial sentence. In addition to solid organs and tissues, the Act applies to the use of other specimens including body fluids if they contain cells. Tissue can be stored and used without consent for a number of purposes on the basis that these are integral to the general provision of clinical and diagnostic services. These include clinical audit, education or training relating to human health, performance assessment and quality assurance. In the case of research, the Act allows tissue to be used without consent, provided that the tissue is anonymized so that the researcher cannot identify from whom the material came. Linking with medical records is allowed, provided patient-identifying information is not obtained. There is a requirement to respect the wishes of any patient who specifies that they do not wish diagnostic or therapeutic samples to be kept or used for additional purposes.
Comparison of Bayer Advia Centaur® immunoassay results obtained on samples collected in four different Becton Dickinson Vacutainer® tubes
Authors: Morovat A , James TS , Cox SD , Norris SG , Rees MC , Gales MA , Taylor RP 
Published: November 2006

Background: Medicines and Healthcare products Regulatory Agency's (MHRA's) Medical Device Alert MDA/2004/048 described bias in some endocrine test results obtained on a few immunoassay platforms, particularly the Bayer Advia Centaur® instrument, when using blood specimens collected into Becton Dickinson (BD) VacutainerTM SSTTMII Advance tubes. As users of BD tubes and the Advia Centaur® instrument, we addressed our concerns about the quality of the results that we had previously reported by undertaking an independent study. Method: We compared the results of 15 immunoassays performed on Bayer Advia Centaur® using blood specimens collected into four different BD Vacutainer® tubes (plain, old and newly released BD SSTTMII Advance, and BD PSTTMII). Results: Compared with plain tubes, old SSTTMII Advance tube results showed no bias for testosterone, CA15-3, follicle-stimulating hormone and folate assays, but gave a positive bias for cortisol and a negative bias for vitamin-B12. Compared with plain tubes, BD PSTTMII tubes gave no significant bias for thyroid function tests, prolactin, parathyroid hormone, and CA125, but gave a negative bias for steroid assays, and a positive bias for gonadotrophins. The results obtained using new BD SSTTMII Advance tubes were generally comparable with those on plain tubes. Conclusions: Only for cortisol did our findings support the bias described by MHRA. Based on our results, apart from vitamin-B12 and possibly cortisol, there may have been no significant influence on clinical decisions as a result of using the old BD SSTTMII Advance specimen tubes. New BD SSTTMII Advance tubes and plain tubes give generally comparable results. BD PSTTMII tubes should not be used for steroid hormone measurements on the Bayer Advia Centaur® instrument.
Assessment of the practicability and analytical performance of a point-of-care affinity chromatography haemoglobin A1c analyser for use in the non-laboratory setting
Authors: Shephard Mark , Whiting Malcolm 
Published: November 2006

Background: Haemoglobin A1c (HbA1c) is a pivotal pathology test used around the world for the long-term management of patients with diabetes. Point-of-care testing (POCT) provides a convenient means for conducting HbA1c testing outside the laboratory. Methods: The practicability and analytical performance of the Micromat II POCT HbA1c analyser (Bio-Rad Laboratories, USA), which has affinity chromatography as its methods principle, was evaluated in Australia and compared with the DCA 2000 POCT device (Bayer Australia) and a laboratory-based high-performance liquid chromatography (HPLC) method. Results: Overall between-day imprecision over 10 days was 1.9% for the laboratory HPLC method, 2.2% for the DCA 2000 and 7.0% for the Micromat II. In a second study over the same time period, the Micromat II's imprecision was 6.4%. The mean difference between the Micromat II and the laboratory method in a patient comparison ( n = 100) was -0.25% (lower and upper limits of agreement -1.79 to 1.30). Conclusions: The imprecision obtained with the Micromat II was inferior to both the DCA 2000 and laboratory methods and did not meet current internationally accepted precision goals for this analyte. The Micromat II's poor imprecision can be explained by the high degree of technical expertise needed to perform the test; its use by non-laboratory health professionals such as nurses and Aboriginal health workers in rural and remote Australia cannot be recommended.
Narrative Forms in Winesburg, Ohio
Authors: Mellard James M. 
Published: November 2006

AbstractSherwood Anderson's Winesburg, Ohio, has not one, but four different narrative forms. The symbolic stories, “The Book of the Grotesque,” “Hands,” “Paper Pills,” “Tandy,” and “Drink,” emphasize the symbols suggested by their titles, lead readers toward crucial thematic epiphanies, and develop several of Anderson's affirmative values. In contrast, the stories of incident, “Nobody Knows,” “Adventure,” “An Awakening,” “The Untold Lie,” and “Departure,” are virtually without symbolism, but have nearly mythically simple narratives in which characters come to some momentary understanding of self, society, or life in general. The thematic stories, “Godliness,” “Respectability,” “The Strength of God,” “Loneliness,” “Death,” and “Sophistication,” subordinate character, event, and symbol to the exposition of the “truth,” quality, or state of being signaled in the titles. The emblematic stories, “Mother,” “The Philosopher,” “A Man of Ideas,” “The Thinker,” “The Teacher,” and “ 'Queer',” focus narrowly on character types, as events, actions, and attitudes, past and present, explain them and emphasize their typical behavior patterns; they usually end with these characters seeking release from their frustrations through violence or flight. The uniformity of each narrative form, focusing as it does on one dominant element, probably lies in the lyrical impressionism of Anderson's method of composition.
Explicación Literal de la Doctrina de la discriçión
Authors: Del Piero Raúl A. 
Published: November 2006

AbstractPedro de Veragüe's Doctrina de la discricon has been rightly regarded as “a most important monument of XIVth century Spanish poetry.” It has heretofore been known through a single manuscript (E) from which it has been edited twice. This study utilizes four new textual sources: a manuscript from the Colegio Mayor de San Bartoiomé: S (the best, despite the influence of the Leonese dialect); a second manuscript from the Gayangos Collection (M); a third from a private collection (R); and the only extant copy of a sixteenth-century printing preserved in the British Museum (L). As appears from the watermarks and script, R (1438-55) and S antedate the known manuscript E. M is a late copy (ca. 1535) of considerable textual value. L was preceded by editions now lost and was probably printed by Varela in Seville ca. 1525. The stemma shows that S, R, M, and L share an ancestor of which E is not a descendant. These four new texts contain new stanzas and clarify the meaning of numerous corrupt passages. The present study gives the new stanzas and some of the most important lectiones varice from S, R, M, and L. Basically a textual comment, it endeavors to explain the difficult passages of the poem and includes notes on its language, versification, and historic background. (In Spanish)
XIII.—The Origin of the Rule Forbidding Hiatus in French Verse
Authors: Marcou P. B. 
Published: November 2006

The rule forbidding hiatus in French verse which has been followed in all literary poetry since Malherbe's day may be thus formulated:—A word ending in a vowel other than an e muet cannot be followed within the same line by a word beginning with a vowel or h muette.Where a word ends in an e muet and the following word begins with a vowel or an h muette, the e muet is elided and the hiatus thus avoided.For the purposes of this rule the t of et is supposed not to exist.Oui is sometimes treated as though it began with a consonant.Hiatus is allowed before or after a few interjections; also in certain set expressions such as peu à peu, cà et là, and the like.
I.—The Name Cædmon
Authors: Cook Albert S. 
Published: November 2006

Two such authorities as the ‘Encyclopædia Britannica ‘and the’ Dictionary of National Biography’ are arrayed against each other with respect to the derivation of our ancient poet's name. In the ‘Encyclopaedia’ we read:“Sir Francis Palgravé, despairing of finding a native derivation, suggested (Archæologia, vol. xxiv.) that the poet might have been so called from the Chaldaic name for the book of Genesis, which is ‘b’ Cadmin,‘in the beginning, or’ Cadmon,‘beginning, from the opening words of the first chapter of Genesis. He thought that he might even have been an’ Eastern visitor,’ who had arrived in Britain from the East, mastered the language, and come out as a vernacular poet. A hypothesis so fanciful as this last may be at once rejected…. On the whole, Sir Francis Palgrave's first suggestion seems to involve the least difficulty. ‘Cadmon’ means ‘beginning’ in the Targum of Onkelos, the Chaldee version of the Scriptures, which was in popular use among the Jews from the 1st century B. C. downwards, and some learned ecclesiastic at Whitby who had visited the Holy Land may have given to the poet the name Cadmon (which in Anglo-Saxon mouths became Cædmon), because he was to sing of the ‘beginning’ of things.”
II.—A Plea for the Study of Literature from the æsthetic Standpoint
Authors: Fruit John P. 
Published: November 2006

That teacher of literature who has not comprehended the significance of a work of Art, has never been endued with the spirit and power of his high calling. He stands unwittingly in the place of an apostle of “that external quality of bodies which may be shown to be in some sort typical of the Divine attributes.”“Those qualities, or types,” according to Ruskin, “on whose combination is dependent the power of mere material loveliness” are:“Infinity, or the type of Divine Incomprehensibility; Unity, or the type of the Divine Comprehensibility; Repose, or the type of the Divine Permanence; Symmetry, or the type of the Divine Justice; Purity, or the type of the Divine Energy; Moderation, or the type of Government by Law.”
Generalization and numerical investigation of QMOM
Authors: Grosch R. , Briesen H. , Marquardt W. , Wulkow M. 
Published: November 2006

AbstractA generalized framework is developed for the quadrature method of moments (QMOM), which is a solution method for population balance models. It further evaluates the applicability of this method to industrial suspension crystallization processes. The framework is based on the concepts of generalized moments and coordinate transformations, which have been used already in earlier solution approaches. It is shown how existing approaches to QMOM are derived from the suggested unified framework. Thus, similarities and differences between the various QMOM methods are uncovered. Further, potential error sources involved in the different approaches to QMOM are discussed and assessed by means of a series of test cases. The test cases are selected to be challenging. The error in the QMOM solution is evaluated by comparison to an adaptive, error controlled solution of the population balance. The behavior of a range of different QMOM formulations is analyzed by means of numerical quadrature, dynamic simulation, as well as numerical continuation and bifurcation analysis. As a result of this detailed analysis, some general limitations of the method are detected and guidelines for its application are developed. This article is limited to lumped population balance models with one internal coordinate. © 2006 American Institute of Chemical Engineers AIChE J, 2007
Assessment of dose proportionality of muraglitazar after repeated oral dosing in rats via a sparse sampling methodology
Authors: Yao Ming , Swaminathan Arun , Srinivas Nuggehally 
Published: November 2006

AbstractMuraglitazar is an α/γ‐dual peroxisome proliferator‐activated receptor (PPAR) agonist. This study evaluated the single‐ and multiple‐dose oral toxicokinetics of muraglitazar in rats at doses of 3, 30 and 300 mg/kg/day. In total, 15 rats/gender/dose group received muraglitazar every day for 1 month. On both day 1 and day 28, blood samples were obtained at 0.5, 2, 4, 6, 8 and 24 h post‐dose, followed by LC/MS analysis. In order to minimize blood loss in the rats, a sparse sampling approach was used to delineate the toxicokinetics.The peak plasma concentration (Cmax) and area under the plasma concentration‐time curve (TAUC0–t) values for muraglitazar increased in a proportion less than the increment in dose. As the dose increased in the ratio 1:10:100, the Cmax for muraglitazar in male and female rats increased in the ratio of 1:10.3:58.6 and 1:15.3:75.3 on day 1, and 1:5.9:28.1 and 1:13.3:37.3 on day 28, respectively. The corresponding TAUC0−t values for males and females were in the ratio of 1:10.2:131 and 1:12.4:131 on day 1, and 1:9.5:93.4 and 1:11.8:94.3 on day 28, respectively. The results indicate that muraglitazar exhibits a dose dependent toxicokinetics in rats and the systemic exposure of muraglitazar was decreased on day 28 compared with day 1. Copyright © 2006 John Wiley & Sons, Ltd.