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Standardization
Terms modified by Standardization Selected AbstractsTOWARD THE GLOBAL STANDARDIZATION OF ENDOSCOPIC SUBMUCOSAL DISSECTION PROPOSAL FOR 10 YEARS FROM NOW , PRESENT AND FUTURE VIEW OF KOREADIGESTIVE ENDOSCOPY, Issue 2009Joo Young Cho Endoscopic submucosal dissection (ESD) is the main treatment of early gastric cancer in Korea. The Korean Society of Gastrointestinal Endoscopy (KSGE) has organized an ESD research group and made several plans to standardize pathologic and therapeutic points of view. This article is to introduce the present and future view of ESD in Korea. [source] Clandestine Artisans or Integrated Producers?: Standardization of Rural Livelihood in the Norte Chico, ChileCULTURE, AGRICULTURE, FOOD & ENVIRONMENT, Issue 1-2 2004Assistant Professor William L. Alexander First page of article [source] Impact of the international program for quality assessment and standardization for immunological measures relevant to HIV/AIDS: QASICYTOMETRY, Issue 2 2002Francis Mandy Abstract Measurements of CD4 T-cell levels are essential for the assessment of human immunodeficiency virus (HIV) disease course, clinical staging, epidemiological studies, and decisions regarding prophylactic therapies against opportunistic infection. Until now, only in the industrialized countries was T-cell subset monitoring considered a practical option to assess disease progression. The Quality Assessment and Standardization for Immunological Measures Relevant to HIV/AIDS (QASI) program was established in 1997 to meet performance assessment for immunophenotyping laboratories in countries where such service is not available. The QASI program is provided at no cost to any laboratory in a resource-poor setting that wishes to participate. This report describes the beneficial impact of participation in the QASI program. Carefully selected commercial stabilized whole blood preparations were sent regularly to participating laboratories. Participants reported the T-cell subset values they obtained by flow cytometry. Once the aggregate mean values for the T-cell subsets were established for the shipment, a comprehensive and confidential report was sent to each laboratory. The results from five consecutive shipments were analyzed. The coefficient of variation decreased from 7.2% to 4.7% and from 14.2% to 8.8% for percent and absolute CD4 T-cell counts, respectively. With the implementation of the QASI program using commercial stabilized whole blood specimens, it is possible to reduce interlaboratory error. This study illustrates that a quality assessment program can improve the overall performance of laboratories. Reducing interlaboratory variation can enhance significantly the effectiveness of multicenter HIV vaccine or drug trial evaluation. Cytometry (Clin. Cytometry) 50:111,116, 2002. © 2002 Wiley-Liss, Inc. [source] Standardization of HbA1c measurements.DIABETIC MEDICINE, Issue 7 2000Reply No abstract is available for this article. [source] Standardization of HbA1c measurement , the issuesDIABETIC MEDICINE, Issue 1 2000Article first published online: 24 DEC 200 No abstract is available for this article. [source] Standardization of HbA1c measurements , a consensus statementDIABETIC MEDICINE, Issue 1 2000S. M. Marshall No abstract is available for this article. [source] CURRENT STATUS AND FUTURE PERSPECTIVE OF INTERVENTIONAL ENDOSCOPIC ULTRASOUND IN JAPANDIGESTIVE ENDOSCOPY, Issue 2009Mitsuhiro Kida Vilmann and Grimm made the first reports of endoscopic ultrasound (EUS)-fine needle aspiration (FNA), and since then EUS-FNA has become popular in the clinical fields, especially in Western countries. Furthermore interventional EUS such as pseudocyst drainage, EUS-guided biliary drainage, celiac plexus neurolysis, and dendritic cell injection, etc. have been introduced. We have investigated the current status and future perspectives of interventional EUS in Japan. Standardization of EUS-guided pseudocyst drainage has been achieved, but EUS-guided biliary dranage is still controversial, and EUS-fine needle injection (FNI) including EUS-celiac plexus neurolysis (CPN) and dendritic cell injection have been under investigation. In any case, EUS-FNA seems to be a promising future technique and new applications have to be invented. [source] Hearing loss in Fabry disease: data from the Fabry Outcome SurveyEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2006S. Hegemann Abstract Background, Hearing loss is a common symptom in Fabry disease, but neither its natural course nor its aetiology has been defined precisely. The aim of this study was to provide a detailed epidemiological description of hearing impairment in patients in the Fabry Outcome Survey (FOS), which is the largest available database of Fabry patients. Materials and methods, Questionnaires were completed by 566 Fabry patients, of whom 316 reported ear-related symptoms. Pure-tone audiograms from 86 patients, performed before starting enzyme replacement therapy, were analysed and compared with age- and sex-specific normal values (International Organization for Standardization, ISO 7029). Results, When compared to an age-matched population (ISO 7029), 74% of patients had a threshold elevated above the 95th centile in at least one tested frequency. All frequencies were affected to a similar degree. However, only 14 patients (16%) were clinically affected by hearing impairment according to the age-independent World Health Organization (WHO) classification (mean threshold at 0·5, 1 and 2 kHz worse than 25 dB). Hearing loss was sensorineural in 63 patients (73%) of whom 7 patients (8%) had also a conductive component. One patient had a purely conductive hearing loss. Episodes of sudden hearing loss seemed to occur more frequently than in the general population. Men were affected earlier and more severely than women. Conclusions, Hearing in Fabry disease is significantly worse than in an age-matched general population but leads to clinically relevant hearing impairment in only 16% of cases. It resembles accelerated presbycusis with an additional Fabry-specific strial-type hearing loss. [source] A method for the analysis of milk and egg allergens for the atopy patch testEXPERIMENTAL DERMATOLOGY, Issue 10 2009Cinzia Ballabio Abstract:, The patch test with food antigens (atopy patch test, APT) has been reported as a more specific method than prick or RAST for the early detection of cow's milk and/or egg sensitizations in children. Standardization of APT extracts is a major issue on the road towards full clinical exploitation of this assay. Here, we used sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to characterize sensitivity and specificity of commercial preparations of APT for milk and egg allergies, which are expected to improve the reliability of this test, when compared with fresh food allergen sources. We found that: (i) SDS-PAGE is an appropriate technique for quality control of APT and (ii) commercial milk and egg APT are equivalent to fresh food preparations in terms of allergen content. Clinical trials aimed at characterizing sensitivity and specificity of APT in the diagnosis of food allergy in children will benefit from this technique. [source] Neccesity for Standardization in Fluorescence Pattern AnalysisIMAGING & MICROSCOPY (ELECTRONIC), Issue 1 2009Petra Perner Dr. Fluorescent pattern analysis is used in cellular and molecular biology as well as in medicine, agriculture or other applications. To make it feasible in daily practice, standardization is necessary to obtain authentically and reproducible results. Standardization has many aspects (fig. 1). It has to do with sample preparation, imaging techniques, knowledge acquisition, and image interpretation. It is an iterative process and cannot be solved from scratch. [source] Evaluation of Ves-Matic Cube 200 , an automated system for the measurement of the erythrocyte sedimentation rateINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1p2 2010E. PEROVIC Summary Ves-Matic Cube 200 is fully automated analyzer that performs erythrocyte sedimentation rate (ESR) measurement using the standard ethylenediaminetetraacetic acid blood sample tube, thus markedly reducing the analytical time and avoiding the need for an extra blood sample. The aim of this study was to assess the automatic Ves-Matic Cube 200 system for the measurement of ESR in comparison with the original International Council for Standardization in Hematology reference method (Westergren). The evaluation comprised accuracy which was established using a 95% confidence interval (CI) for the mean difference between Ves-Matic Cube 200 and Westergren method (mean of difference: 0.47 ± 6.84 mm/h; 95% CI: ,0.376 to 1.325 mm/h), within-run imprecision for samples with ESR values of 9, 42 and 95 mm/h (coefficients of variation: 9.19%, 13.88% and 5.66%, respectively) and method comparison (, = 0.95; Passing-Bablok regression equation: Y = ,0.0435 + 1.0435 X; bias: ,0.5; limits of agreement: ,13.9 to 12.9). Stability was estimated after 24 h storage either at 4 °C and room temperature (mean of differences: ,1.91 mm/h; 95% CI: ,4.852 to 1.037 mm/h and mean of differences: ,12.48 mm/h; 95% CI: ,16.580 to ,8.390 mm/h, respectively). The obtained results suggest that the Ves-Matic Cube 200 automated analyzer is reliable system for the measurement of ESR in clinical laboratories. [source] EQAS for peripheral blood morphology in Spain: a 6-year experienceINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2008G. GUTIÉRREZ Summary The Spanish haematology external quality assessment scheme (EQAS), established in 1984, is run by the Spanish Haematology and Haemotherapy Association (AEHH) [Quality Assurance in Health Care 3 (1991) 75] and functions to evaluate the quality and reproducibility of the assessment of diagnostic samples by clinical laboratories. The Hospital Clinic of the University of Barcelona (HCB) serves as the EQAS Coordination Centre and follows the guidelines established by the International Committee for Standardization in Haematology [Annali dell'Istituto superiore di Sanità 31 (1995) 95; International Journal of Hematology 68 (1998) 45]. During the period 2001,2006, replicates of 25 different blood films were sent to 604 EQAS participants for cell morphology evaluation. Some patient details corresponding to the samples were disclosed, such us age, sex, haemoglobin value and white blood cell count. The participants were asked to select up to four significant morphology features using a coding list, provided by the Coordination Centre, which included significant morphological alterations that appear in haematopoietic cells. For each survey, individual results were assessed against the morphological reference results (MRR) established by the Cytology Group of the AEHH (,true' answers). This paper describes the organization of the 6-year-long study and the evaluation of laboratory performance for blood smear interpretation by the Spanish haematology EQAS. Different performance levels were detected relative to the laboratory category. Laboratories providing services to hospitalized patients showed higher performances compared with laboratories providing services to nonhospitalized patients. Pathological lymphoid cells were the most difficult to identify by the participants. To improve the results in EQAS peripheral blood morphology, the development of specific cytology educational trainings is discussed. [source] Comparison of the reticulocyte mode of the Abx Pentra 120 Retic, Coulter® General-SÔ, Sysmex® SE 9500, Abbott CD 4000 and Bayer Advia® 120 haematology analysers in a simultaneous evaluationINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2001J. Van Den Bossche The Abx Pentra 120 Retic, Coulter® General-SÔ, Sysmex® SE 9500, Abbott Cell Dyn® 4000 and Bayer Advia® 120 were evaluated simultaneously in a general hospital laboratory. Linearity, precision, sample stability, carry-over and comparability of the reticulocyte mode were determined following International Council for Standardization in Haematology guidelines for the evaluation of blood cell analysers. All analysers showed good results for dilution, stability and carry-over testing. The between-batch coefficient of variation of the General-SÔ was high compared to the other analysers evaluated. Multiple correlation studies showed good agreement for all analysers in the normal and high reticulocyte range, with correlation coefficients above 0.7. Multiple correlation studies for reticulocytopenic samples (< 15.109/l) were less satisfactory, with a wider range of correlation coefficients (r -values 0.0,0.9). Overall, the General-SÔ, SE 9500 and Advia® 120 gave lower reticulocyte counts than the Pentra 120 Retic and CD 4000. Reagent costs were also evaluated. Reagent consumption was close to the manufacturers' specifications for the SE 9500 (Search reagent), CD 4000 (CD Retic) and Advia® 120 (Retics) but was higher than stated for the Pentra 120 Retic (Retix), General-SÔ (Retic kit) and SE 9500 (Sheath reagent). Our results show that these new generation haematology analysers will meet the needs of hospital laboratories for reliable and cost-effective reticulocyte counting. [source] Carrier phase recovery for turbo-coded systems with pre-coded GMSK modulationINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 6 2008Zhuo Wu Abstract A carrier phase recovery scheme suited for turbo-coded systems with pre-coded Gaussian minimum shift keying (GMSK) modulation is proposed and evaluated in terms of bit-error-rate (BER) performance. This scheme involves utilizing the extrinsic information obtained from the turbo-decoder to aid an iterative carrier phase estimation process, based on a maximum-likelihood (ML) strategy. The phase estimator works jointly with the turbo-decoder, using the updated extrinsic information from the turbo-decoder in every iterative decoding. A pre-coder is used to remove the inherent differential encoding of the GMSK modulation. Two bandwidths of GMSK signals are considered: BT=0.5 and 0.25, which are recommended by the European Cooperation for Space Standardization (ECSS). It is shown that the performance of this technique is quite close to the perfect synchronized system within a wide range of phase errors. This technique is further developed to recover nearly any phase error in [,,,+,] by increasing the number of phase estimators and joint decoding units. This, however, will increase the complexity of the system. Copyright © 2008 John Wiley & Sons, Ltd. [source] Guidelines for management of urinary incontinenceINTERNATIONAL JOURNAL OF UROLOGY, Issue 10 2008Osamu Nishizawa In Japan, only the following two guidelines are available: ,Guidelines on Urinary Incontinence in the Elderly' based on research funded by the Longevity Sciences Research Grant (chief investigator: Kikuo Okamura) and ,Guidelines on Urinary Incontinence in Women' based on ,Research on Treatment Standardization in the Urological Field' funded by the Health Sciences Research Grant (group leader: Osamu Nishizawa). This paper is an English translation of these two guidelines originally published in Japanese. [source] Standardization and differences in nursing: a dilemma that needs more researchINTERNATIONAL NURSING REVIEW, Issue 2 2007Jane J.A. Robinson FRCN, PhD Editor No abstract is available for this article. [source] Survey augmentation using commercial vessels in the Mid-Atlantic Bight: Sampling density and relative catchabilityJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2006E. N. Powell Summary A series of side-by-side tows was conducted between a survey vessel and a commercial vessel in two seasons, spring and fall (autumn), to examine the use of commercial vessels to increase sampling density in trawl-based stock surveys. Both vessels caught more fish offshore in the spring. The commercial vessel caught more fish than the survey vessel in both seasons. Catches of nearly all species were contagiously distributed in the spring. Most were contagiously distributed in the fall; however, somewhat more species were characterized by random or even distributions. The variance-to-mean ratio was consistently higher for most species for commercial vessel catches, regardless of season. As both vessels sampled in the same region at the same time, the increased predilection for the survey vessel to assess the distribution pattern as less patchy than the commercial vessel must accrue from some difference in sampling dynamics rather than variation in species distribution. A simulated decrease in sampling effort from 59 to 30 or 15 hauls increased the variance-to-mean ratio. Reduced sampling effort increased the tendency for occasional large catches to vary the estimate of domain biomass. The sampling program included an onshore,offshore gradient in station density. Domain biomass was considerably underestimated with reduced station density for six species characterized by large catches offshore in that portion of the survey domain characterized by low station density. In this study, a factor of two variation in domain biomass became more likely in 40% of species when sampling effort was reduced to 15 hauls from 59. A factor of two in biomass may distinguish a sustainable fishery from one in which a species is overfished. As survey sampling effort in this area was 18 hauls, increasing sample number by inclusion of commercial vessel tows would be advantageous. A regression between paired tows failed to adequately predict catches of one vessel from catches of the other. Standardization of vessel catches by the ratio-of-mean catches provided a more realistic comparison because large catches accounted for a significant fraction of domain biomass; however, a single conversion coefficient between boats could not be used for both sampling periods. The underlying impediment in developing a general conversion factor between the two vessels seems to be rooted in the differential in variance-to-mean ratios of the catches; this differential exists despite sampling of the same distribution of fish. [source] Standardization of line-scan NIR imaging systemsJOURNAL OF CHEMOMETRICS, Issue 3-4 2007Zheng Liu Abstract A simple and easy to use method is proposed for standardizing NIR imaging systems for differences among detectors in the charge-coupled device (CCD) array and illumination unevenness. The standardization equations are then used to pre-treat NIR image data to reduce the systematic errors introduced by a line-scan NIR imaging system. The method requires only easily available homogeneous standards with relatively uniform spectral response. The effectiveness of the standardization in reducing the pixel-to-pixel biases and other systematic effects is illustrated with examples, and the improved sensitivity in results obtained from a multivariate image analysis (MIA) based on multi-way principal component analysis (MPCA) is demonstrated. Copyright © 2007 John Wiley & Sons, Ltd. [source] Standardization of Network Technologies: Market Processes or the Result of Inter-Firm Co-operation?JOURNAL OF ECONOMIC SURVEYS, Issue 4 2001Bertrand Quélin As recent studies on the evolution of a technology indicate, the role of a standard, or dominant design, is highly significant in a number of contemporary industries such as computer, telecommunications and consumer electronics. Following Katz' and Shapiro's pioneering works (1985), our paper rationally evaluates the concepts and results developed over the past ten years in this field. It is grounded on a typology of two types of models: the first is based on users' anticipatory behaviour, and the second, on the collaborative behaviour of existing firms. The article initially discusses the specificity of network technologies, then analyses market standardisation models, and finally, studies the different actors models. Our conclusion builds upon existing works in network technologies. We next propose a research agenda [source] "Revenue Accounting" in the Age of E-Commerce: A Framework for Conceptual, Analytical, and Exchange Rate ConsiderationsJOURNAL OF INTERNATIONAL FINANCIAL MANAGEMENT & ACCOUNTING, Issue 1 2002Jonathan C. Glover This paper explores "revenue accounting" in contrast to traditional "cost accounting". Revenue accounting serves the information needs of managers and investors in planning and controlling a firm's sales activities and their financial consequences, especially in the age of e-commerce. Weaknesses of traditional accounting have become particularly evident recently, for example, the lack of 1) revenue mileposts, 2) revenue sustainability measurements, and 3) intangibles capitalization. The paper emphasizes the need to develop a conceptual framework of revenue accounting and, as a tentative measure, proposes five basic postulates and five operational postulates of revenue accounting. On the side of analytical frameworks, the paper explores some tentative remedies for the weaknesses. Several revenue mileposts are explored to gauge progress in earning revenues and a Markov process is applied to an example involving mileposts. Revenue momentum, measured by the exponential smoothing method, is examined as a way of getting feedback on revenue sustainability; and the use of the sustainability concept in the analysis of "fixed and variable revenues" is illustrated. A project-oriented approach in a manner similar to capital budgeting and to Reserve Recognition Accounting is proposed by treating each customer as a project. Standardization of forecasts are also considered as an important way of bypassing the capitalization issue. Finally, while e-commerce is inherently global, issues specific to global operations are highlighted, namely, exchange rate issues when venture capitalists and the start-up company use different currencies producing different rates of return on the same project. [source] Metasemiotic Regimentation in the Standardization of Nepali Sign LanguageJOURNAL OF LINGUISTIC ANTHROPOLOGY, Issue 2 2008Erika Hoffmann-Dilloway Both the linguistic forms attended to and the ways in which they are linked to the social vary within and across language standardization projects. In addition, it cannot be assumed that people will notice the same indexical connections between linguistic forms and social structures or rationalize them in the same ways. An analysis of the project to standardize Nepali Sign Language highlights the fact that it is therefore necessary to account for the processes by which standardization projects attempt to reduce variation not only in the formal properties of language but also in the wider semiotic interpretations of those forms.[Nepal, d/Deaf, standardization, language ideologies, semiotic indeterminacy] [source] Physical properties and compatibility with dental stones of current alginate impression materialsJOURNAL OF ORAL REHABILITATION, Issue 11 2004H. Murata summary, This study examined physical properties and compatibility with dental stones of two types of alginate impression materials. Five powder-type alginate impression materials (Alginoplast EM, Aroma Fine, Algiace Z, Coe Alginate, Jeltrate Plus) and a paste-type alginate impression material (Tokuso AP-1) were used. The dynamic viscosity immediately after mixing was measured by means of a controlled-stress rheometer. The gelation times were determined according to Japanese Industrial Standards (JIS) T6505, and recovery from deformation, strain in compression and compressive strength were determined according to the International Organization for Standardization (ISO) specification 1563. Detail reproduction and surface roughness of type III dental stones (New Plastone, New Sunstone) and a type IV dental stone (Die Stone) were evaluated using a ruled test block as specified in the ISO specification 1563 and a profilometer, respectively. The alginate impression materials evaluated in this study were all in compliance with the ISO specification 1563 and JIS T6505. The alginate impression materials had similar mechanical properties after gelation, whilst a wide range of dynamic viscosity immediately after being mixed, gelation times and compatibility with dental stones were found among the materials. The paste-type material had a higher dynamic viscosity and a shorter gelation time than the powder-type materials. The best surface quality was obtained with the paste-type material/type III dental stone cast combinations. The materials should be selected in consideration of initial flow, setting characteristics and compatibility with dental stones. The results suggested that a paste-type material would better meet the requirements of an alginate impression material. [source] Curing depth of different shades of a photo-activated prosthetic composite materialJOURNAL OF ORAL REHABILITATION, Issue 7 2001N. Tanoue This study determined the depth of cure of different shades of a prosthetic composite material with the aim of evaluating the influence of shade variation on post-curing material properties. Four light shades having small tabs (A1, B1, C1 and D2) and four dark shades having higher tabs (A4, B4, C4 and D4) of a prosthetic composite (Artglass) for body paste based on the Vita Lumin Shade guide were selected. Specimens of each shade were exposed with the proprietary photo-curing unit (UniXS) for periods 20, 30, 60 and 90 s. The curing depth of the material for each shade was determined with a scraping technique described by the International Organization for Standardization (ISO 4049), and average values of groups of five specimens were compared using analysis of variance (ANOVA) and Scheffe's S intervals (P < 0·05). The L*a*b* colour parameters of five specimens after 90 s exposure were measured using a small-area dental colorimeter (ShadeEye) in order to determine the colorimetric differences. Three-factor ANOVA revealed that the depth of cure was influenced by shade letter (A, B, C or D) and shade tab (1 and 2, or 4) as well as by the exposure period (P=0·05). Curing depth of the light shades was consistently greater than that of the dark shades. Among the eight shades selected, B1 shade demonstrated the greatest curing depth, while A4 shade exhibited the lowest curing depth. For all shades, longer exposure increased the depth of cure. All of the light shades exhibited higher L* values than any of the four dark shades. Curing depth of the composite material was found to be related to the Vita shade variation and the exposure period. [source] The European standard for sun-protective clothing: EN 13758JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2 2006T Gambichler Abstract Clothing is considered one of the most important tools for sun protection. Contrary to popular opinion, however, some summer fabrics provide insufficient ultraviolet (UV) protection. The European Committee for Standardization (CEN), has developed a new standard on requirements for test methods and labelling of sun-protective garments. This document has now been completed and is published. Within CEN, a working group, CEN/TC 248 WG14 ,UV protective clothing', was set up with the mission to produce standards on the UV-protective properties of textile materials. This working group started its activities in 1998 and included 30 experts (dermatologists, physicists, textile technologists, fabric manufacturers and retailers of apparel textiles) from 11 European member states. Within this working group, all medical, ethical, technical and economical aspects of standardization of UV-protective clothing were discussed on the basis of the expertise of each member and in consideration of the relevant literature in this field. Decisions were made in consensus. The first part of the standard (EN 13758-1) deals with all details of test methods (e.g. spectrophotometric measurements) for textile materials and part 2 (EN 13758-2) covers classification and marking of apparel textiles. UV-protective cloths for which compliance with this standard is claimed must fulfill all stringent instructions of testing, classification and marking, including a UV protection factor (UPF) larger than 40 (UPF 40+), average UVA transmission lower than 5%, and design requirements as specified in part 2 of the standard. A pictogram, which is marked with the number of the standard EN 13758-2 and the UPF of 40+, shall be attached to the garment if it is in compliance with the standard. The dermatology community should take cognizance of this new standard document. Garment manufacturers and retailers may now follow these official guidelines for testing and labelling of UV-protective summer clothes, and the sun-aware consumer can easily recognize garments that definitely provide sufficient UV protection. [source] Standardization of circulating endothelial cell enumeration by the use of human umbilical vein endothelial cellsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2007P. K. Y. GOON No abstract is available for this article. [source] A collaborative study to establish the 7th International Standard for Factor VIII ConcentrateJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2005S. Raut Summary., A candidate concentrate, preparation N (99/678), was assayed and calibrated, as a potential replacement, against four established factor (F) VIII concentrate standards: the current WHO 6th International Standard (IS) (97/616), the previous 5th IS (88/640), the Mega 1 standard and Ph. Eur. BRP Batch 2 standard, in a collaborative study involving 38 laboratories. All laboratories were instructed to use the ISTH/SSC recommendations, including predilution of concentrates in FVIII-deficient plasma. Several laboratories performed more than one assay method and altogether there were 27 sets of assays with the one-stage method, 31 with the chromogenic method, and 18 with both methods. There was good agreement between laboratories using each of the two methods for comparison of preparation N against the four established standards, with overall potencies by one-stage and chromogenic methods differing only by less than 2%. However, there were significant differences in potencies relative to the different standards, ranging from 10.1 IU per ampoule against the Ph. Eur.BRP2 to 11.4 against the WHO 6th IS. Accelerated degradation studies showed that the proposed standard is very stable, with a predicted loss of activity per year of less than 0.001% at the recommended storage temperature of ,20 °C. Various options for potency of preparation N were considered by the participants and by members of the ISTH/SSC FVIII/FIX Subcommittee. In November 2003, preparation N (NIBSC 99/678) was proposed to and accepted by the Expert Committee on Biological Standardization of the World Health Organization to be the 7th International Standard for Factor VIII Concentrate with an assigned potency of 11.0 IU per ampoule. [source] Statistical study of organomolybdenum compounds in an engine oil formulation and the results of engine testingLUBRICATION SCIENCE, Issue 1 2001M. S. Saini Abstract Organomolybdenum compounds are versatile lubricant additives of interest in the design of engine oils to meet the new ILSAC (International Lubricant Standardization and Approval Committee) GF-3 performance standard, especially for fuel efficiency. In this work, organomolybdenum and 13 other components were studied by experimental design and statistical analysis to determine their effects on friction, wear, and oxidation properties. The resulting linear model was used to construct a trial engine oil formulation. Engine test results, including some new tests required for ILSAC GF-3, confirmed some of the strengths of organomolybdenum compounds, as well as their sensitivity to other additives in the formulation. [source] Standardization of allergen products: 1.ALLERGY, Issue 7 2009Detailed characterization of GMP-produced recombinant Bet v 1.0101 as biological reference preparation Background:, Standardization of allergen extracts requires the availability of well-characterized recombinant allergens, which can be used as reference standards provided by the European regulatory authorities. The objective of this study was the detailed physicochemical and immunological characterization of rBet v 1.0101, which shall be used in a ring trial within the framework of the Biological Standardization Programme BSP090 of the European Directorate for Quality of Medicines and Healthcare. Methods:, Recombinant Bet v 1.0101 Y0487 was produced under good manufacturing practice conditions and analysed by an array of physicochemical and immunological methods for identity, quantity, homogeneity, folding and denaturation, aggregation state and stability in solution, as well as biological activity. Results:, Batch Y0487 was shown to contain monomeric and well-folded protein being identical with rBet v 1.0101, as determined by mass spectrometry. SDS-PAGE, isoelectric focusing, deamidation analysis and size-exclusion chromatography with light scattering revealed sample homogeneity of >99.9%. Upon storage at +4°C batch Y0487 retained the monomeric state up to 3 months. Protein quantification determined by amino acid analysis was found coinciding with half-maximal inhibition of serum IgE in ELISA. Biological activity of batch Y0487 was shown to be comparable to natural Bet v 1 by IgG and IgE immunoblotting, as well as basophil and T-cell activation. Conclusion:, Recombinant Bet v 1.0101 Y0487 was characterized extensively by physicochemical and immunological methods. It was shown highly stable, monomeric and immunologically equivalent to its natural counterpart. Thus, it represents an appropriate candidate reference standard for Bet v 1. [source] Simple means to improve the interpretability of regression coefficientsMETHODS IN ECOLOGY AND EVOLUTION, Issue 2 2010Holger Schielzeth Summary 1. Linear regression models are an important statistical tool in evolutionary and ecological studies. Unfortunately, these models often yield some uninterpretable estimates and hypothesis tests, especially when models contain interactions or polynomial terms. Furthermore, the standard errors for treatment groups, although often of interest for including in a publication, are not directly available in a standard linear model. 2. Centring and standardization of input variables are simple means to improve the interpretability of regression coefficients. Further, refitting the model with a slightly modified model structure allows extracting the appropriate standard errors for treatment groups directly from the model. 3. Centring will make main effects biologically interpretable even when involved in interactions and thus avoids the potential misinterpretation of main effects. This also applies to the estimation of linear effects in the presence of polynomials. Categorical input variables can also be centred and this sometimes assists interpretation. 4. Standardization (z -transformation) of input variables results in the estimation of standardized slopes or standardized partial regression coefficients. Standardized slopes are comparable in magnitude within models as well as between studies. They have some advantages over partial correlation coefficients and are often the more interesting standardized effect size. 5. The thoughtful removal of intercepts or main effects allows extracting treatment means or treatment slopes and their appropriate standard errors directly from a linear model. This provides a simple alternative to the more complicated calculation of standard errors from contrasts and main effects. 6. The simple methods presented here put the focus on parameter estimation (point estimates as well as confidence intervals) rather than on significance thresholds. They allow fitting complex, but meaningful models that can be concisely presented and interpreted. The presented methods can also be applied to generalised linear models (GLM) and linear mixed models. [source] Standardization of anal sphincter electromyography: Utility of motor unit potential parametersMUSCLE AND NERVE, Issue 7 2001Simon Podnar MD Abstract Advanced electromyography systems offer quantitative analysis of a number of motor unit potential (MUP) parameters. However, only limited data are available on the diagnostic usefulness of these parameters. In the present study, we compared the sensitivities of MUP parameters in revealing "neuropathic" changes in the external anal sphincter (EAS) muscles in 56 patients examined 5,240 months after damage to the cauda equina or conus medullaris. Using multi-MUP analysis, 20 MUPs were obtained from patients' EAS muscles. Their MUP parameters were compared with normative data from 64 controls. The diagnostic sensitivities of mean values/"outliers" of MUP parameters for detecting neuropathic EAS muscles were calculated (area 25%/30%; number of turns 18%/29%; size index 13%/24%; thickness 18%/18%; amplitude 17%/17%; spike duration 20%/9%; duration 15%/12%; number of phases 15%/11%; and their combination 51%/52%). Altogether, the cumulative sensitivity of multi-MUP analysis using both mean values and "outliers" was 62%. The combination of MUP parameters improves the diagnostic yield of MUP analysis, but the influence on specificity remains unknown. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 946,951, 2001 [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||