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PubMed1991

Standardization of factor IX: standards for "purified" factor IX concentrates.

An international collaborative study was carried out to determine the suitability of the current WHO II-IX-X concentrate standard, 84/681, for assigning potency to the more highly purified factor IX concentrates. Three Coagulation Factor IX (Human) preparations and one Factor IX Complex preparation were assayed by the one stage method against WHO 84/681 following predilution to 1.0 u/ml in buffer, 1% albumin, or factor IX deficient plasma. There were no cases of non-parallelism between any of the preparations and the current WHO standard. Predilution of the Coagulation Factor IX (Human) preparations in 1% albumin or factor IX deficient plasma gave similar potency values. Predilution in buffer gave significantly lower (p less than 0.01) potency values. For the Factor IX Complex preparation, potency estimates were significantly different (p less than 0.01) with each prediluent. The overall precision was similar within each predilution for all preparations with predilution in buffer being less precise than predilution in albumin or in deficient plasma. WHO standard 84/681 appears to be a suitable standard for the potency determination of the more highly purified factor IX preparations. Predilution in 1% albumin or factor IX deficient plasma is recommended as they give equivalent results with the least variability.

Factor IX↗

PubMedDate not supplied

National Bureau of Standards reference materials as organic nutrient standards: a preliminary study.

A preliminary study was conducted to determine if the available National Bureau of Standards (NBS) Standard Reference Materials (SRM) Non-Fat Powdered Milk, Oyster Tissue, Wheat Flour, Rice Flour, Spinach, and Albacore Tuna would be suitable for use as organic nutrient standards. These materials were assayed for folates, total pantothenates, vitamin B6, thiamine, riboflavin, niacin, and protein. Vitamins A, E, D, K, and C were also assayed but, for the most part, were not detected. Based on results from this study, it appears that at least some of the NBS SRMs would be useful as organic nutrient standards.

Animals↗

PubMed1993

Ought 'standard care' be the 'standard of care'? A study of the time to administration of antibiotics in children with meningitis.

OBJECTIVE: To determine the time from triage in an emergency department until administration of parenteral antibiotics in children with bacterial meningitis. RESEARCH DESIGN: Retrospective review of medical records and survey of medical subspecialists in infectious diseases and emergency medicine. SETTING: Emergency departments of two university-affiliated pediatric hospitals. PARTICIPANTS: All children with bacterial meningitis identified in medical records from 1987 to 1989 (N = 93). MEASUREMENTS: For each child, the time from presentation to the emergency department until administration of antibiotics (AB time) was determined; when possible, time from triage to contact with a physician, from triage to lumbar puncture, and from lumbar puncture to administration of antibiotics was measured. We then surveyed specialists in both pediatric infectious diseases (n = 23) and pediatric emergency medicine (n = 54) as to their beliefs about AB time in children with meningitis. STATISTICAL ANALYSES: Mann-Whitney Rank Sum Test and Kruskal-Wallis Test. RESULTS: Median AB time was 2.0 hours (interquartile range, 1.25 to 3.33 hours). Only one (1%) of 93 children received antibiotics within 30 minutes of presentation. Median time from triage until contact with a physician was 0.45 hour. Median time from lumbar puncture until antibiotics administration was about 0.5 hour. The estimates of median AB time differed significantly between emergency medicine (0.93 hour) and infectious disease (1.45 hours) experts, and estimates from both differed significantly from the median AB time (2.0 hours) actually observed. CONCLUSIONS: These data reveal that the usual and customary practice (ie, standard medical care) by qualified physicians may differ from opinions of standard medical care promulgated by medical experts. Even among experts there is a wide range of (mistaken) opinions about standard medical care. Insofar as jurors in medical malpractice cases are instructed to consider what physicians "ordinarily do in similar circumstances," a data-based definition of "standard" medical care should supplant anecdotal testimony by individual expert witnesses.

Anti-Bacterial Agents↗

PubMed1990

Data file standard for flow cytometry. Data File Standards Committee of the Society for Analytical Cytology.

This data file standard for flow cytometry (FCS) provides a detailed description of a data file structure designed such that the file can include all of the information necessary to describe fully: 1) the instrument used to obtain the data; 2) the sample measured; 3) the data obtained; and 4) the results of analysis of the data. The file may contain one or more data sets. Each data set includes data from a single sample or acquisition run. Each data set consists of a minimum of four parts--HEADER, TEXT, DATA, and ANALYSIS--all of which are required. The file is structured such that the parts of a data set do not have to be in any particular order, except for the HEADER, which must always be first. The HEADER contains pointers to the beginning and end of each of the other three parts. The file is written as a continuous byte stream, with no line or page formating. The HEADER, TEXT, and ANALYSIS parts are written in ASCII format and the DATA part can be written in ASCII, binary integer or floating point. This Standard, noted as FCS2.0, is based on a standard proposed by Murphy and Chused (Cytometry 5:553-555, 1984). Data written utilizing their proposed format (FCS1.0) is compatible with the format described here. Future versions of the standard will maintain compatibility with older versions.

Flow Cytometry↗

PubMed1980

Implementation of Canadian Standards Association Z168.3-M 1980 Anaesthetic Gas Machine Standard: the Manitoba experience.

The Province of Manitoba Anaesthetic Machine Program, completed in June 1980, accommodated Canadian Standards Association Standard Z168.3-M 1980. "Continuous Flow Inhalation Anesthetic Apparatus (Anesthetic Machines) for Medical Use". The goal of the program was to have all anaesthetic machines in hospitals in the province with the same basic design and safety features: "oxygen right"; characteristic oxygen knob profile; oxygen supply pressure failure device and alarm; standardized "oxygen flush" mechanism; pipeline inlets and pressure gauges; uniform color coding; standardized common gas outlet; pin indexed cylinder yokes; descriptive labels concerning safety devices; check valves within machine piping. Open group-purchase tenders were invited for both machine upgrading and replacement. Of 212 machines surveyed, 127 were upgraded (cost $100,000), 65 were replaced (cost $175,000), three were already satisfactory, and 17 were no longer required and were removed permanently from service. The Manitoba Program provided a satisfactory solution to a most important problem.

Anesthesia, Inhalation↗

PubMed1986

Determination of Cd-thionein in biological materials: comparative standard recovery by five current methods using protein nitrogen for standard calibration.

Five methods of metallothionein (MT) estimation in biological materials (Hg-saturation assay, Cd-saturation assay, thiolate group determination, Sephadex G-75 gel chromatography with subsequent Cd determination by Zeeman-AAS, and a radioimmunoassay (RIA) were compared for their ability to recover standard MT(rabbit Cd-MTI) from liver or kidney S9. Uniform molar calibration of all assays was achieved using the known amino acid composition of standard MT and the nitrogen content of the standard MT stock solution as measured after complete Kjeldahl digestion. Known molar amounts of standard MT were added exogenously to rat liver- or kidney-S9 samples and recoveries measured using the methods indicated. In an overall rating, RIA and Cd-saturation assay performed best with recoveries of 97 +/- 12.0 and 105 +/- 9.7%, respectively. On the other hand, the remaining methods either underestimated (thiolate group determination, G-75/Cd-AAS) or overestimated (Hg-saturation assay) the theoretical expectation by up to 44%.

Animals↗

PubMed1989

Calibration of 125I-polymer standards with 125I-brain paste standards for use in quantitative receptor autoradiography.

125I-Polymer standards were calibrated by interpolation of their optical densities in [125I]-brain paste standard curves to obtain dpm/mg protein. There was a linear relationship between the calibrated polymer standards and the dpm/mg polymer, as provided by the manufacturer. One dpm/mg polymer was equivalent to 7.34 +/- 0.22 dpm/mg protein. Receptor quantification in selected rat brain areas with comparison to either brain paste or calibrated polymer standards yielded similar results.

Animals↗

PubMed1990

Separate hemoglobin standards for blacks and whites: a critical review of the case for separate and unequal hemoglobin standards.

There have been a number of reports that suggest mean differences between the hemoglobin (Hgb) levels of black and white Americans. Many of those reports have had as their basis various national US nutrition surveys. Early reports indicated that blacks had a 1.0 g/dl lower mean Hgb than whites. Later reports put the mean Hgb difference between 0.5 and 0.73 g/dl. Recent reports, in which either iron intake or iron status have been measured and controlled, indicate a mean Hgb difference of between 0.2 and 0.3 g/dl. Despite the variability in these mean Hgb differences, some reports call for the establishment of separate Hgb standards for black Americans. The need for separate Hgb standards is critically reviewed in light of alternative interpretations of early data and newer knowledge about the development, detection, and significance of iron deficiency. The suitability of national cross-sectional survey data to answer questions about Hgb standards without adequate experimental studies in questioned, especially since no genetic studies have been performed to indicate genetic differences in Hgb levels. Policy implications of a change from current standards are also discussed.

Adolescent↗

PubMed2001

Analysis of standard and non-standard visual word format in the two hemispheres.

A dual-route model for the recognition of written words is hypothesised. The model postulates that the two cerebral hemispheres differ in their sensitivity to the visual format of verbal stimuli. Such stimuli may be 'standard', that is in Standard Visual Format (SVF), or "non-standard", i.e. in non-standard Visual Format (NSVF). In the left hemisphere (LH), SVF words are routed directly to the lexicon, while NSVF words must go through an additional encoding phase prior to lexicon access. In the right hemisphere (RH) all words (SVF and NSVF) must proceed to an additional encoding phase prior to accessing the lexicon. Two lateralized lexical decision experiments are reported. In Section 2, angle of orientation was used to define SVF and NSVF. In Section 3, presentation of verbal stimuli was preceded by a cue indicating whether the coming lexical stimulus was in SVF or NSVF, while SVF was defined as in Section 2. The results showed that the difference in RT, favouring RVF stimulation was found for orientations up to 30 degrees. Greater angles of presentation significantly reduced RVF superiority. The largest differences between responses to stimuli presented to the two visual fields was found when word stimuli were in SVF (up to 30 degrees ) and presented after a priming cue. The results are discussed in terms of the model, but alternative explanations are suggested.

Adult↗

PubMedDate not supplied

[Behavior of mortality indicators in small geographic areas: relative standardized mortality ratio and standardized proportional mortality ratio].

One of the most commonly used indicators in mortality studies is the Standardized Mortality Ratio (SMR) being the Relative Standardized Mortality Ratio (RSMR) an indicator of the relative magnitude of the SMR for a specific cause of death. Along with these indicators, which must be calculated by using the population at risk, there is the Standardized Proportional Mortality Ratio (SPMR), an indicator which measures the excess mortality referring to the proportional mortality established for a standard population. This paper reviews the theoretic conditions described in literature as being necessary to establish a probability interval for the RSMR centered on the SPMR as well as the correlations between both indicators and the use of the SPMR as a predictor of the RSMR. The results obtained clearly show how difficult it is for these theoretic conditions to exist. However, they do suggest that the SPMR be used as a predictor of RSMR.

Cause of Death↗

PubMed2000

Search for a standard phytotoxic bioassay for allelochemicals. Selection of standard target species.

In the search for a standard bioassay of phytotoxicity for allelochemicals, 22 commercial varieties of eight plant species [four dicotyledons: lettuce (Compositae), carrot (Umbelliferae), cress (Cruciferae), tomato (Solanaceae); and four monocotyledons: onion (Liliaceae), barley, wheat, and corn (Gramineae)] proposed as models for the most common weed families have been tested at different pH and solution volumes per set conditions. Nine commercial varieties selected as standard target species (STS) were tested with standard commercial herbicides to ensure their sensitivity to phytotoxic compounds. Results are discussed to establish the proper growth requirements, and sensitivity of commercial seeds of STS and to find the most suitable commercial herbicides that allow comparison with an internal standard to validate the response of potential allelochemicals.

Biological Assay↗

PubMed2001

Standardized evaluation and documentation of findings in patients with craniosynostosis.

Surgical correction of craniosynostosis is usually performed according to standard procedures. However, a standard for clinical examination and report of findings for patients with craniosynostosis does not exist as yet. To compare findings from different hospitals, a documentation system was developed by a national craniosynostosis group. This system comprises a two-page document, clinical photographs, radiographs, CT scans, anthropometric measurements and molecular genetic findings. Data from craniosynostosis patients collected from participating hospitals are stored in a database, which facilitates online access.The documentation system was developed in cooperation with the group during 3 years since 1996. It was evaluated as being practicable and reliable and enables a comparability of findings reported in different hospitals. Molecular genetic analysis was found to support the investigation of patients with craniosynostosis and should therefore be integrated in the clinical evaluation. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.

Journal Article↗

PubMedDate not supplied

[The Graf standard plane--a "standard sector"? Ultrasound studies of anatomic preparations of hip acetabula of infants].

AIM: To answer the question as to which ultrasound sections, related to the hip joint plane, lead to pictures of the so-called "standard-plan" of Graf, anatomic preparations of infant hips were examined by ultrasound. METHOD: 10 anatomic preparations of infant hips were fixed in a support which allows an exact positioning of the ultrasound plane related to the acetabular inlet plane in a water bath. The joints were examined while changing the relative position in steps of 10 degrees. The ultrasound images were documented by video-print and the alpha-angles were measured if the criterias of the standard plane were fulfilled. RESULTS: In order to obtain images that are analysable by the method of Graf, the ultrasound beam has to intersect with the acetabular inlet plane at defined angles. The acetabular notch has to be anteriorly rotated from the ultrasound beam plane by at least 20 degrees. Beam entry within a 50-degree sector posterior to the perpendicular on the inlet plane gave analysable images. The alpha-angles were markedly affected by coronal-plane transducer tilt. Caudad tilts were associate with lower values, a fact that should be borne in mind in clinical ultrasound investigations. CONCLUSION: The "standard plane" of graf is a "standard sector", which can be defined in all three dimensions. The relations between the acetabular inlet plane and the sonographic beam are described exactly for the first time. The results are important because of their influence on clinical ultrasound examinations.

Acetabulum↗

PubMed1997

The best-interests standard as threshold, ideal, and standard of reasonableness.

The best-interests standard is a widely used ethical, legal, and social basis for policy and decision-making involving children and other incompetent persons. It is under attack, however, as self-defeating, individualistic, unknowable, vague, dangerous, and open to abuse. The author defends this standard by identifying its employment, first, as a threshold for intervention and judgment (as in child abuse and neglect rulings), second, as an ideal to establish policies or prima facie duties, and, third, as a standard of reasonableness. Criticisms of the best-interests standard are reconsidered after clarifying these different meanings.

Child↗

PubMed1983

Inoculum standardization in antimicrobial susceptibility testing: evaluation of overnight agar cultures and the Rapid Inoculum Standardization System.

Using the Rapid Inoculum Standardization System [RISS; Minnesota Mining & Manufacturing Co. (3M Co.)], we investigated the use of overnight agar cultures in the preparation of inocula for disk diffusion and microdilution susceptibility tests and compared our results with susceptibility results obtained with the standard methods. The 3M system consists of an inoculation wand, with which a reproducible number of bacteria can be removed from an agar plate, and a diluent in which to suspend the organisms. We used 25 gram-positive cocci, 75 enteric and nonfermentive gram-negative bacilli, and 40 more fastidious bacteria (Haemophilus, Neisseria, and pneumococci) for the evaluation. The geometric mean inoculum size for all organisms tested was 9.7 X 10(7) CFU/ml by the standard method and 1.1 X 10(8) CFU/ml for the RISS. The categories of susceptibility obtained by both methods in the disk diffusion tests were comparable, as were the minimal inhibitory concentrations. We recommend that the use of overnight agar cultures and the use of the RISS to prepare inocula for susceptibility tests be acceptable alternative procedures in the standard methods for susceptibility tests.

Agar↗

PubMed1994

Selection of candidate quality control isolates and tentative quality control ranges for in vitro susceptibility testing of yeast isolates by National Committee for Clinical Laboratory Standards proposed standard methods.

The National Committee for Clinical Laboratory Standards has developed a proposed standard method for in vitro antifungal susceptibility testing of yeast isolates (National Committee for Clinical Laboratory Standards, document M27-P, 1992). In order for antifungal testing by the M27-P method to be accepted, reliable quality control (QC) performance criteria must be developed. In the present study, five laboratories tested 10 candidate QC strains 20 times each against three antifungal agents: amphotericin B, fluconazole, and 5-fluorocytosine. All sites conformed to the M27-P standards and used a common lot of tube dilution reagents and RPMI 1640 broth medium. Overall, 98% of MIC results with amphotericin B, 95% with fluconazole, and 92% with 5-fluorocytosine fell within the desired 3-log2 dilution range (mode +/- 1 log2 dilution). Excellent performance with all three antifungal agents was observed for six strains: Candida albicans ATCC 90028, Candida parapsilosis ATCC 90018, C. parapsilosis ATCC 22019, Candida krusei ATCC 6258, Candida tropicalis ATCC 750, and Saccharomyces cerevisiae ATCC 9763. With these strains, 3-log2 dilution ranges encompassing 94 to 100% of MICs for all three drugs were established. Additional studies with multiple lots of RPMI 1640 test medium will be required to establish definitive QC ranges.

Amphotericin B↗

PubMed2003

Controlled clinical comparison of BacT/ALERT standard aerobic medium with BACTEC standard aerobic medium for culturing blood.

Standard aerobic media are widely used for culturing blood with the BacT/ALERT (BioMérieux, Inc., Durham, N.C.) (BM) and BACTEC 9240 (BD Diagnostic Systems, Sparks, Md.) (BD) automated continuously monitoring instrument systems. Although similarly composed of soybean-casein digest broths, the formulations of the standard aerobic media available for these instruments differ from each other in supplements and in sodium polyanetholesulfonate concentration. Therefore, we compared the standard aerobic media available for these systems at two university hospitals. Blood samples from adult patients with suspected bloodstream infection were inoculated at the bedside into nonvented BM and BD standard aerobic blood culture bottles and incubated in their respective instruments. The laboratories received 6,743 pairs of bottles that were each filled with 8 to 12 ml of blood. A total of 523 isolates representing true infections were recovered from 257 patients; of these isolates, 348 were recovered from both the BD and the BM bottles, 108 were recovered from the BM bottles only, and 67 were recovered from the BD bottles only (P < 0.005). More staphylococci (P < 0.05), especially coagulase-negative staphylococci (P < 0.05), and yeasts (P < 0.01) were recovered from BM bottles than from BD bottles. Of 291 unimicrobial episodes of bloodstream infection, 220 were detected with both bottles, 41 were detected with the BM bottles only, and 30 were detected with the BD bottles only (difference not significant). Among 335 cultures that were positive in both bottles within the first 72 h of incubation, the median times to detection were 14 h for BM bottles and 13 h for BD bottles. Rates for false-positive results were 0.5% for BM bottles and 0.1% for BD bottles. One BM bottle and seven BD bottles yielded false-negative results. We conclude that the BM medium provides improved recovery of microorganisms, especially staphylococci and yeasts, compared with that provided by the BD medium.

Aerobiosis↗

PubMed1994

Cytogenetic nomenclature of deer mice, Peromyscus (Rodentia): revision and review of the standardized karyotype. Report of the Committee for the Standardization of Chromosomes of Peromyscus.

A revision of the standardized karyotype of deer mice (Peromyscus) is presented. This revision addresses short-comings of the original standardization, contains a substantial increase in the number of G-band markers and provides a nomenclature for the G-bands of each autosome and the X chromosome. Using the revised standardized karyotype, we specify the particular G-bands or patterns that identify each chromosome and catalog the more problematic chromosome identifications and likely misidentifications. For each chromosome, we present an overview of previously reported variation in euchromatic arrangement and heterochromatic constitution. We then review previous applications of the standardized karyotype and summarize the predominant findings from cytogenetic and cytosystematic studies of Peromyscus and related taxa.

Animals↗