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At least 217 records · Page 12Linked to original sources
PubMed1982

Standard-suspension-test: influence of bovine albumin, saline and water of standard hardness on M.E.-values.

Notwithstanding considerable international agreement upon the principle of the quantitative suspension test differences still exist between the main variants of this test, in particular on the diluent to be used in the test mixture. For this reason the influence of the main variables - i.e. bovine albumin (0.03%), NaCl (physiol. saline) and divalent ions (water of standard hardness) - on the activity of the different classes of disinfectants have been investigated. Using so-called borderline concentrations only a small protein effect of 0.03% bovine albumin was found with a phenolic product, quaternary ammonium compounds and aldehydes. A substantial protein effect was observed only with chlorine compounds. The chlorine consumption in the present Dutch Standard Suspension Test is approx. 20 ppm. In tests without a protein load as well as in the presence of 0.03% bovine albumin M.E.-values using saline as the diluent were usually higher than in tests using water of standard hardness (WSH) or distilled water (DW). M.E.-values of quaternary ammonium compounds in WSH were significantly lower than those in DW, presumably due to the antagonizing effect of divalent cations (Mg++ and Ca++). The different views regarding the aim of quantitative suspension tests are discussed. In The Netherlands the opinion prevails that these tests should have at least some relationship with practical conditions. The use of water of standard hardness as a diluent and the incorporation of a slight protein challenge are in agreement with this standpoint.

Disinfectants↗
PubMed1995

Recommendations for standardized human pedigree nomenclature. Pedigree Standardization Task Force of the National Society of Genetic Counselors.

The construction of an accurate family pedigree is a fundamental component of a clinical genetic evaluation and of human genetic research. Previous surveys of genetic counselors and human genetic publications have demonstrated significant inconsistencies in the usage of common pedigree symbols representing situations such as pregnancy, termination of pregnancy, miscarriage, and adoption, as well as less common scenarios such as pregnancies conceived through assisted reproductive technologies. The Pedigree Standardization Task Force (PSTF) was organized through the Professional Issues Committee of the National Society of Genetic Counselors, to establish recommendations for universal standards in human pedigree nomenclature. Nomenclature was chosen based on current usage, consistency among symbols, computer compatibility, and the adaptability of symbols to reflect the rapid technical advances in human genetics. Preliminary recommendations were presented for review at three national meetings of human genetic professionals and sent to > 100 human genetic professionals for review. On the basis of this review process, the recommendations of the PSTF for standardized human pedigree nomenclature are presented here. By incorporating these recommendations into medical genetics professional training programs, board examinations, genetic publications, and pedigree software, the adoption of uniform pedigree nomenclature can begin. Usage of standardized pedigree nomenclature will reduce the chances for incorrect interpretation of patient and family medical and genetic information. It may also improve the quality of patient care provided by genetic professionals and facilitate communication between researchers involved with genetic family studies.

Genetic Counseling↗
PubMed1995

IS&C (Image Save & Carry) standard: standardized exchange media for medical information.

There has been a strong need for a standardized medical image exchange media. MEDIS-DC in Japan created IS&C as a standard for this purpose, based on 5.25' rewritable magneto-optic discs, with many specifications such as fast speed read/write, independence of apparatus vendor, additional security features, and data format compatible to ACR-NEMA v.2 image format. IS&C is already applied to many institutions, as an alternative for fast expensive networks, long term image casebases and media for teaching file distribution. The IS&C committee hopes this standard will be: 1) used at clinics and hospitals, promoting exchange of information between them, 2) harmonized with other standardization activities, and 3) a basis for future electronic semantic medical records.

Computer Communication Networks↗
PubMed1997

[Anales de Medicina Interna: standardization, dissemination and bibliometric indicators. (I) Standards evaluation].

The evaluation of scientific journal has become a necessary exercise for a variety of purposes and parties. We evaluated compliance with ISO standards for periodicals by the Spanish biomedical journal An. Med. Interna. Compliance with 136 data items based on different standards was evaluated with the help of a specially developed data sheet, and expressed as overall mean compliance (49.2%) and actual mean compliance (83.4%), i.e., compliance with those items considered necessary for the effective transfer of information via data bases. Items for which standardization was not optimal were examined in detail and specific recommendations for correction were given. We conclude that An. Med. Interna effectively fulfills its mission as an instrument for the communication of research results. In comparison with Spanish journals covering different areas and published by different organizations, compliance with international standards was better in An. Med. Interna.

Bibliometrics↗
PubMedDate not supplied

Rapid infusion of streptokinase standard dose in acute myocardial infarction is followed by a higher rate of coronary reperfusion than standard protocol.

There are several opinions asserting that the accelerated t-PA is more efficient than the standard protocol of streptokinase (SK) administration in acute myocardial infarction (AMI). One hundred patients admitted within the first 6 hrs after the onset of the symptoms revealing AMI were divided in two subgroups, as follows: subgroup A (50 patients) in whom a dose of 1.5 M.U. SK was infused in 20 min (accelerated protocol) and subgroup B (50 patients) in whom the same dose was infused in 60 min (standard protocol). In order to assess the efficiency of thrombolytic therapy (TT), we used three noninvasive criteria: the rapid resolution of the chest pain, the rapid decreasing of the ST segment elevation by more than 50% from the initial value, and the rapid increasing of enzymes revealing necrosis. Using the above-mentioned criteria, we considered that coronary reperfusion appeared in 40 patients from subgroup A (80%) and in 29 patients from subgroup B (58%). The speed of coronary reperfusion was 40 +/- 26 min in patients with accelerated SK and this time was significantly shorter than the time of 60 +/- 24 min registered in the control group. No major hemorrhagic events appeared in both subgroups. Although hypotension appeared more frequently in subgroup A, this minor complication was well supported by our patients. The rapid infusion of the standard dose of SK was followed by a higher rate and speed of coronary reperfusion as compared to the standard protocol.

Aged↗
PubMed2001

Third International Standard for pertussis vaccine: international confirmation study of activity of British Standard for pertussis vaccine, coded 66/303.

The first British Standard (BS) (Code 66/303) for pertussis whole cell vaccine was prepared from the same suspension of Bordetella pertussis as the now exhausted Second International Standard for Pertussis Vaccine (2ndIS). The BS and the 2ndIS were compared and calibrated in a previous international study. This report describes a small international study, which included the BS, the 1stIS and the 2ndIS so that the present relationship of these preparations to one another could be assessed. The results of this study show that the relationship of the BS to the 1stIS is consistent with its established unitage of 46 IU per ampoule. The results further show that the potency of the BS is broadly consistent with that of the 2ndIS and that the BS has not lost activity relative to the 2ndIS (from which it was previously found to be indistinguishable). Based on its original calibration and supported by the results of this present study, the BS has been established as the Third International Standard for Pertussis Vaccine, with an assigned unitage of 46 IU per ampoule.

Humans↗
PubMed2006

The Calibration Kit Spectral Fluorescence Standards--a simple and certified tool for the standardization of the spectral characteristics of fluorescence instruments.

With the Calibration Kit Spectral Fluorescence Standards BAM-F001-BAM-F005, we developed a simple tool for the characterization of the relative spectral responsivity and the long-term stability of the emission channel of fluorescence instruments under routine measurement conditions thereby providing the basis for an improved comparability of fluorescence measurements and eventually standardization. This first set of traceable fluorescence standards, which links fluorescence measurements to the spectral radiance scale in the spectral range of 300-770 nm and has been optimized for spectrofluorometers, can be employed for different measurement geometries and can be adapted to different fluorescence techniques with proper consideration of the underlying measurement principles.

Calibration↗
PubMed1984

Standard electromotive force of the H2-AgCl;Ag cell in 30, 40, and 50 mass% dimethyl sulfoxide/water from -20 to 25 degrees C: pK2 and pH values for a standard "Bicine" buffer solution at subzero temperatures.

The establishment of the pH (designated pH*) of a standard buffer solution suitable as a pH reference in 30, 40, and 50 mass% dimethyl sulfoxide (DMSO)/H2O mixtures at temperatures in the range -20 to 0 degrees C is reported. The buffer material selected was the ampholyte Bicine (N,N-bis(2-hydroxyethyl)glycine), and the reference standard consists of equal molal quantities of Bicine and its sodium salt. The assignment of pH* values rests on measurements of the emf of cells without liquid junction, Pt;H2(g, 1 atm) [Bicine, Na Bicinate, NaCl [AgCl;Ag, and the pH* was derived from a determination of K2, the equilibrium constant for the dissociation process (Bicine) +/- in equilibrium (Bicinate)- + H+. The standard emf in the DMSO/H2O solvents at subzero temperatures was determined from emf measurements of the cell with solutions of HCl replacing the buffer-chloride mixture.

Buffers↗
PubMed2006

Standards and measurements for assessing bone health-workshop report co-sponsored by the International Society for Clinical Densitometry (ISCD) and the National Institute of Standards and Technology (NIST).

This article reports and discusses the results of the recent ISCD-NIST Workshop on Standards and Measurements for Assessing Bone Health. The purpose of the workshop was to assess the status of efforts to standardize and compare results from dual-energy X-ray absorptiometry (DXA) scans, and then to identify and prioritize ongoing measurement and standards needs.

Absorptiometry, Photon↗
PubMed2001

Prediction of internal standards in reversed-phase liquid chromatography. 1. Initial study on predicting internal standards for use with neutral samples based on linear solvation energy relationships.

This paper describes the results of an initial study on the application of linear solvation energy relationships (LSERs) to the prediction of internal standard compounds in reversed-phase liquid chromatographic (RPLC) method development. Six neutral samples are separated on an Inertsil ODS(3) column by either acetonitrile-water or methanol-water mobile phases under either isocratic or linear gradient conditions. After the separation conditions are optimized, the desired positions for internal standard candidates are selected based on the "open windows" of the chromatograms. The compounds with the desired retention range are then predicted based on LSERs from a database consisting of more than 700 compounds with defined physicochemical properties. The prediction requires the use of LSER coefficients under the separation conditions for each sample. They are determined a priori by performing multivariable linear regression on the retention of 20 reference solutes against their physicochemical properties. It can be concluded from the study that LSER is an excellent approach to the selection of internal standard compounds for RPLC under either isocratic or gradient elution. The average prediction error is usually within 10%, but no more than 20%. Finally, LSER approach is fast and systematic, and will save a significant amount of time and resources during RPLC method development.

Chromatography, Liquid↗
PubMed2002

Prediction of internal standards in reversed-phase liquid chromatography. II. Selectivity optimization and internal standard prediction for the quantitation of estradiol and levonorgestrel in a transdermal drug delivery formulation based on the linear solvation energy relationships.

This paper describes the results of selectivity optimization and internal standard prediction for the quantitation of estradiol and levonorgestrel in transdermal patches by reversed-phase liquid chromatography (RPLC) based on the linear solvation energy relationships (LSERs). The patch samples are prepared by swelling with acetonitrile (ACN) and the separation is performed by Zorbax Eclipse XDB ODS columns. A proper retention range is first determined with a binary mobile phase of ACN and water based on the general resolution equation. The interference to estradiol from a levonorgestrel impurity is then eliminated by a ternary mobile phase of acetonitrile-methanol-water with a composition predicted by LSERs. When the resolution is optimized and the "open window" in the chromatogram for an internal standard is selected, LSERs are used to predict the candidate compounds to be evaluated as the internal standard. The approach described in this study can be used, in general, to considerably improve the efficiency of RPLC method development, particularly for neutral samples. Finally, the LSER approach for the selectivity optimization is compared with a statistical response surface methodology (RSM) based on a central composite design (CCD) in terms of the effectiveness and number of experiments. It is concluded that, although the predicted mobile phase composition to achieve the desired selectivity is about the same, the LSER approach is more efficient and fewer experiments are required.

Chromatography, Liquid↗
PubMed2001

BIOMED-I concerted action report: flow cytometric immunophenotyping of precursor B-ALL with standardized triple-stainings. BIOMED-1 Concerted Action Investigation of Minimal Residual Disease in Acute Leukemia: International Standardization and Clinical Evaluation.

The flow cytometric detection of minimal residual disease (MRD) in precursor-B-acute lymphoblastic leukemias (precursor-B-ALL) mainly relies on the identification of minor leukemic cell populations that can be discriminated from their normal counterparts on the basis of phenotypic aberrancies observed at diagnosis. This technique is not very complex, but discordancies are frequently observed between laboratories, due to the lack of standardized methodological procedures and technical conditions. To develop standardized flow cytometric techniques for MRD detection, a European BIOMED-1 Concerted Action was initiated with the participation of laboratories from six different countries. The goal of this concerted action was to define aberrant phenotypic profiles in a series of 264 consecutive de novo precursor-B-ALL cases, systematically studied with one to five triple-labelings (TdT/CD10/CD19, CD10/CD20/CD19, CD34/CD38/CD19, CD34/CD22/CD19 and CD19/CD34/CD45) using common flow cytometric protocols in all participating laboratories. The use of four or five triple-stainings allowed the identification of aberrant phenotypes in virtually all cases tested (127 out of 130, 98%). These phenotypic aberrancies could be identified in at least two and often three triple-labelings per case. When the analysis was based on two or three triple-stainings, lower incidences of aberrancies were identified (75% and 81% of cases, respectively) that could be detected in one and sometimes two triple-stainings per case. The most informative triple staining was the TdT/CD10/CD19 combination, which enabled the identification of aberrancies in 78% of cases. The frequencies of phenotypic aberrations detected with the other four triple-stainings were 64% for CD10/CD20/CD19, 56% for CD34/CD38/CD19, 46% for CD34/CD22/CD19, and 22% for CD19/CD34/CD45. In addition, cross-lineage antigen expression was detected in 45% of cases, mainly coexpression of the myeloid antigens CD13 and/or CD33 (40%). Parallel flow cytometric studies in different laboratories finally resulted in highly concordant results (>90%) for all five antibody combinations, indicating the high reproducibility of our approach. In conclusion, the technique presented here with triple-labelings forms an excellent basis for standardized flow cytometric MRD studies in multicenter international treatment protocols for precursor-B-ALL patients.

Antigens, CD↗
PubMed2001

National Institute for Biological Standards and Control/UK Blood Transfusion Service working standards for HBsAg, anti-HCV and anti-HIV-1 ('go/no-go' controls).

BACKGROUND AND OBJECTIVES: The positive controls supplied with the commercial kits used in the testing of blood donations for markers of viral infection are usually of high reactivity and do not give users a reliable indication of optimal performance of the kit on a day-to-day basis. MATERIALS AND METHODS: The National Institute for Biological Standards and Control has developed working standards for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (anti-HCV) and anti-human immunodeficiency virus type 1 (anti-HIV-1) for the UK Blood Transfusion Services for daily use in every test. RESULTS: Data from the use of these reagents are collated and quarterly reports are issued. CONCLUSIONS: The centralized collation, analysis and reporting of the results from users of working standards facilitate the continual assessment of the responses obtained by individual laboratories, comparisons of the interlaboratory performance and the performance of different manufacturers' kits at a national level. This information complements the data on infection surveillance and initial/repeat reactivities using the same kits.

Biological Assay↗
PubMed1994

Review of the problems involved in using enzymes in blood group serology--provision of freeze-dried ICSH/ISBT protease enzyme and anti-D reference standards. International Council for Standardization in Haematology. International Society of Blood Transfusion.

Proteolytic enzyme preparations and techniques used routinely in blood group serology for the detection of atypical patient antibodies prior to transfusion vary widely and are often poorly standardised. Recent advances have been made in the use of biochemical methods to standardise and stabilise the potency of the enzyme preparations used. A joint working party of the International Council for Standardization in Haematology (ICSH) and the International Society of Blood Transfusion (ISBT) has investigated possibilities for the provision of standards for the protease preparations and techniques. The specification for these standards was that the performance of enzyme reference preparation in the reference technique should be of equivalent sensitivity to the ICSH/ISBT LISS spin indirect antiglobulin test using a titration series of a reference weak anti-D, and be free from false-positive reactions. The working party circulated materials for evaluation in inter-laboratory trials, followed by a laboratory workshop meeting to achieve agreement on the specification for reference materials and methods. Reference freeze-dried papain at 0.6 azoalbumin units and weak anti-D preparations (91/562) have been prepared and validated to meet these specifications. The performance of a test enzyme preparation in the technique for which it is recommended for use should be at least equal to that of the reference papain preparation, by the reference two-stage technique in terms of sensitivity, using a titration series of the reference anti-D, and freedom from false-positive reactions, using six fresh inert sera. The reference papain and weak anti-D can also be used to calibrate the level of proteolytic activity required in other procedures in blood group serology, such as new technology methods for antibody detection, and automated and microplate cell grouping procedures. These preparations and an agreed method for their use are now available from listed centres as ICSH/ISBT and Food and Drug Administration reference materials.

Blood Grouping and Crossmatching↗
PubMed2003

Cancer biomarker validation: standards and process: roles for the National Institute of Standards and Technology (NIST).

Rigorous validation of biomarkers for early detection of cancer differs at the National Institute of Standards and Technology (NIST) from similar processes common among research laboratories. As a newly discovered biomarker assay makes the transition from a research setting to the clinical diagnostic laboratory, it should progress through defined stages of assay confirmation. The first task of a validation laboratory is evaluation of research assay technology, performance, and specifications (analytical validation). However, the ultimate goal is initial validation of the test to identify early stage cancer (clinical validation). Upon technical and clinical confirmation, assays are moved systematically toward a standardized, reproducible, high-throughput format for clinical diagnostic implementation. With laboratory performance rigorously established, the clinical variables can subsequently be analyzed to define limitations, applications, and clinical utility. The role of NIST in technology evaluation for early cancer testing is described in the context of similar programs and prior experience at NIST. Here we conceptualize the validation steps of cancer test development and examine how NIST activities impact health care through institutional focus on measurement, technology, and standards development programs.

Biomarkers, Tumor↗
PubMed1985

Comparison of several control standard endotoxins to the National Reference Standard Endotoxin--an HIMA collaborative study.

A collaborative study, initiated under the auspices of the Health Industry Manufacturers Association (HIMA), was designed to establish the relationship of Escherichia coli O55:B5 endotoxin (the control standard endotoxin of HIMA and the Food and Drug Administration's Office of Medical Devices) to the U.S. National Reference Standard Endotoxin and to two internationally used control standard endotoxins. By using two Limulus amoebocyte lysate test systems, it was established that the E. coli O55:B5 endotoxin lot originally used by HIMA and the Office of Medical Devices to establish Limulus amoebocyte lysate release test criteria for pyrogen testing of medical devices contains approximately 4.5 endotoxin units (EU) per ng. Thus, the 1.0-ng/kg endotoxin dose limit currently established for medical devices is approximately the same as the 5.0-EU/kg endotoxin limit (on an activity basis) established by several other Food and Drug Administration agencies for human and animal parenteral drugs and biological products.

Endotoxins↗
PubMed2002

Standards for reporting interventions in controlled trials of acupuncture: The STRICTA recommendations. STandards for Reporting Interventions in Controlled Trails of Acupuncture.

Acupuncture treatment and control group interventions in parallel-group randomised trials of acupuncture are not always precisely reported. In an attempt to improve standards, an international group of experienced acupuncturists and researchers devised a set of recommendations, designating them STRICTA: STandards for Reporting Interventions in Controlled Trials of Acupuncture. In a further consensus-building round, the editors of several journals helped redraft the recommendations. These follow the Consolidated Standards for Reporting Trials (CONSORT) format, acting as an extension of the CONSORT guidelines for the specific requirements of acupuncture studies. Participating journal editors are publishing the STRICTA recommendations and requesting prospective authors to adhere to them when preparing reports for publication. Other journals are invited to adopt these recommendations. The intended outcome is that interventions in controlled trials of acupuncture will be more adequately reported, thereby facilitating an improvement in critical appraisal, analysis and replication of trials.

Acupuncture Therapy↗