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At least 19 recordsLinked to original sources
PubMed1978

International standard for anti-Brucella abortus serum: comparison of the complement-fixing activity of the first and second international standards and the EEC standard.

Although the three standards have similar agglutinating activities, it was found that the first International Standard had about half the complement-fixing activity of the second International Standard and the EEC standard. The complement-fixing activities of the latter two standards were similar. On the basis of these results, showing that the agglutination and complement-fixation tests measure different biological activities in anti-Brucella abortus sera, the WHO Expert Committee on Biological Standardization in 1976 assigned separate unitages of agglutinating and complement-fixing activity to the second International Standard for Anti-Brucella abortus Serum.

Agglutination Tests↗
PubMed1997

Gender- and race-based standards of competence: lower minimum standards but higher ability standards for devalued groups.

Stereotypes may influence judgment via assimilation, such that individual group members are evaluated consistently with stereotypes, or via contrast, such that targets are displaced from the overall group expectation. Two models of judgment--the shifting standards model and status characteristics theory--provide some insight into predicting and interpreting these apparently contradictory effects. In 2 studies involving a simulated applicant-evaluation setting, we predicted and found that participants set lower minimum-competency standards, but higher ability standards, for female than for male and for Black than for White applicants. Thus, although it may be easier for low- than high-status group members to meet (low) standards, these same people must work harder to prove that their performance is ability based.

Female↗
PubMed1990

[National Institute of Hygienic Sciences Standard (the Japanese Pharmacopoeia Standard) "Endotoxin Reference Standard" (Control 891)].

The second "Endotoxin Reference Standard" (Control 891) of the National Hygienic Sciences (Japanese Pharmacopoeia Standard) was prepared. As a result of the test of its potency against the preceding lot of the Reference Standard (Control 881), the second "Endotoxin Reference Standard" (Control 891) containing 16000 endotoxin units per vial was authorized.

Endotoxins↗
PubMed1988

Suggested standards for reports dealing with cerebrovascular disease. Subcommittee on Reporting Standards for Cerebrovascular Disease, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery/North American Chapter, International Society for Cardiovascular Surgery.

The evaluation of clinical reports on vascular disease is often made difficult by variations in descriptive terms, clinical classification, and outcome criteria. In 1983 the Joint Council of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery created the Ad Hoc Committee on Reporting Standards to address these problems and recommend solutions. Some general problems were addressed in the initial report dealing with lower extremity ischemia. This article concerns clinical standards for reports dealing with cerebrovascular disease, suggests a scheme for clinical classification, and recommends standardized reporting practices for grading risk factors, angiographic and other diagnostic findings, and the results and complications of therapeutic intervention.

Cerebrovascular Disorders↗
PubMed1991

Suggested standards for reporting on arterial aneurysms. Subcommittee on Reporting Standards for Arterial Aneurysms, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery and North American Chapter, International Society for Cardiovascular Surgery.

The literature on arterial aneurysms is subject to potential misinterpretation because of inconsistencies in reporting standards. The joint councils of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery appointed an ad hoc committee to address this issue. This communication, prepared in response to the need for standardized reporting, defines and classifies arterial aneurysms and recommends standards for describing the causes, manifestations, treatment, and outcome criteria that are important when publishing data on aneurysmal disease.

Aneurysm↗
PubMed1997

[Studies on the molecular weight standards for size-exclusion chromatography--standardization of a molecular weight standard for water-soluble polymers].

The possibility of the standardization of molecular weight standards for size-exclusion chromatography (SEC) was investigated in the case of water-soluble polysaccharides such as dextran, hyaluronate and chitosan. In the case of dextran, comparing the method adopted for dextran in EP and BP, it was shown that pullulan, one of commercially available molecular weight standards, can be used in usual SEC method. For hyaluronate and chitosan, applying the Mark-Houwink correction to the calibration curve obtained by pullulan, the acceptable molecular weights could be estimated.

Chitin↗
PubMed1982

Standard deviation, standard error. Which 'standard' should we use?

Standard deviation (SD) and standard error (SE) are quietly but extensively used in biomedical publications. These terms and notations are used as descriptive statistics (summarizing numerical data), and they are used as inferential statistics (estimating population parameters from samples). I review the use and misuse of SD and SE in several authoritative medical journals and make suggestions to help clarify the usage and meaning of SD and SE in biomedical reports.

Research↗
PubMed1998

How standard is a standard day during a standard ambulatory 24-hour esophageal pH monitoring?

BACKGROUND: Ambulatory 24-h esophageal pH monitoring is the gold standard method for measuring esophageal exposure to gastric acid. The method has gained acceptability because of its sensitivity, specificity, and accuracy and also because it is easy to perform, well tolerated, and quite physiologic. However, whether ambulatory esophageal pH-metry affects normal lifestyle has not been specifically evaluated. METHODS: We investigated 114 consecutive patients admitted to our Unit because of heartburn, acid regurgitation, or non-cardiac chest pain. Patients filled in a diary chart on 2 different days: 1 day while the pH-metry was performed and another normal day, to record the following variables: number, amount, and composition of the meals; time in supine position; number of cigarettes smoked; alcohol intake; degree of physical activity; and number and type of symptomatic episodes. Patients were encouraged to carry out normal activity. RESULTS: When the 2 days were compared, none of the registered variables appeared to differ, with the exception of subjective evaluation of physical activity: 65% of the patients said their physical activity was diminished during the test day relative to their usual standard. CONCLUSIONS: Normal habits are not significantly modified by 24-h esophageal pH-metry, with the exception of physical activity, which decreases, possibly owing more to aesthetic than to physical problems.

Activities of Daily Living↗
PubMed1996

Maintaining standards: differences between the standard deviation and standard error, and when to use each.

Many people confuse the standard deviation (SD) and the standard error of the mean (SE) and are unsure which, if either, to use in presenting data in graphical or tabular form. The SD is an index of the variability of the original data points and should be reported in all studies. The SE reflects the variability of the mean values, as if the study were repeated a large number of times. By itself, the SE is not particularly useful; however, it is used in constructing 95% and 99% confidence intervals (CIs), which indicate a range of values within which the "true" value lies. The CI shows the reader how accurate the estimates of the population values actually are. If graphs are used, error bars equal to plus and minus 2 SEs (which show the 95% CI) should be drawn around mean values. Both statistical significance testing and CIs are useful because they assist the reader in determining the meaning of the findings.

Confidence Intervals↗
PubMed1997

International reference standards: antibody standards for the indirect enzyme-linked immunosorbent assay.

Reference standards are used to calibrate similar assay systems against an international reference protocol and to provide a template for the preparation of secondary and/or working standards. Three reference standards are recommended for the indirect enzyme-linked immunosorbent assay: a strong positive standard, a weak positive standard and a negative serum standard. The negative standard should be derived from a single serum or from a serum pool which exhibits typical background activity in the reference protocol. The strong and weak positive standards should be derived from a single serum or from a serum pool which typifies the humoral response (antibody) to natural infection. Suitable candidates for the positive reference standards should exhibit dose/response curves in the mid-range of antibody activity. The strong and weak positive standards should each be prepared from a one-time dilution in the negative standard, to yield antibody activities which are defined by specific points on the linear portion of the dose/response curve. The strong positive standard should represent an antibody activity (absorbance value) midway between the upper and central points and the weak positive standard should represent an antibody activity midway between the central and lower points of the linear portion of the curve. Owing to inherent differences among assay systems, antibody activities should be expressed in relative rather than in absolute terms. It is recommended that the antibody activity of the strong positive standard should denote 100% positivity. The activities of the weak positive and negative standards should then be expressed as relative percentages. Every set of international reference standards should be accompanied by an information sheet which includes, among other things, a plot of the dose/response curve and an indication of the dilutions used to prepare the standards.

Animals↗
PubMed1990

Standard karyotype of the domestic horse (Equus caballus). Committee for standardized karyotype of Equus caballus. The Second International Conference for Standardization of Domestic Animal Karyotypes, INRA, Jouy-en Josas, France, 22nd-26th May 1989.

The following decisions concerning the banded karyotype of the horse (Equus caballus) were made at the second International conference for Standardization of Domestic Animal Karyotypes, held at Jouy-en Josas, France, 22nd-26th May 1989: (1) numbering of the chromosomes was modified to correspond to an arrangement into only two groups (the non-acrocentrics and the acrocentrics) within which the autosomes are placed according to length alone; (2) a more compact karyotype arrangement was adopted: chromosomes 1 to 5 on the first row, 6 to 10 on the second, 11 to 13, and, at the far right, X and Y on the third row, 14 to 19 on the fourth row, chromosomes 20 to 25 on the fifth, and 26 to 31 on the sixth row; (3) the NOR-bearing horse chromosomes were identified as numbers 1, 28 and 31.

Animals↗
PubMed1988

Reporting standards in venous disease. Prepared by the Subcommittee on Reporting Standards in Venous Disease, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery/North American Chapter, International Society for Cardiovascular Surgery.

This report comprises suggested reporting standards for publications dealing with (1) acute lower extremity venous thrombosis, (2) chronic lower extremity venous insufficiency, (3) upper extremity venous thrombosis, and (4) pulmonary embolism. Attempts have been made to set forth numeric grading schemes for disease severity, risk factors, and outcome criteria. Some of the recommendations had to be arbitrary of necessity, but they were judged the most generally acceptable by members of the committee. They are offered not as binding rules but as guidelines whose observance will serve the clarity and precision of communication.

Adult↗
PubMed1997

Reduction of interlaboratory variability in flow cytometric immunophenotyping by standardization of instrument set-up and calibration, and standard list mode data analysis.

Two workshops addressed the question to which degree standardization of instrument set-up and calibration, and standard list mode data analysis would reduce interlaboratory variability of flow cytometric results on prestained peripheral blood mononuclear cells (PBMC). Standard instrument set-up included uniform positioning of the "windows of analysis" for the forward and sideward light scatter and fluorescence (FL) 1 (i.e., fluorescein isothiocyanate [FITC]) and 2 (i.e., phycoerythrin [PE]) parameters. Reference standards and PBMC, double-stained with FITC- and PE-conjugated monoclonal antibodies covering a wide range of FL intensities and coexpression patterns, were sent out to 25 laboratories in Workshop 1 and to 35 laboratories in Workshop 2 with the following requests: a) to set up instruments according to local and standard protocols, b) to acquire list mode data on the PBMC with both instrument settings, and c) to analyze both datasets according to local protocols. Standard analysis of the list mode data acquired with uniform instrument settings was performed centrally using so-called "latent class model" software (Van Putten et al., Cytometry 14:86-96, 1993). This software provides an automated, "no-gating" analytical method of lymphocyte immunophenotypes and employs fixed FL marker settings as defined prior to each analytical run. In Workshop 1, these markers were set in identical histogram channels for all instruments based on results obtained with a reference instrument. Standard analysis of list mode data acquired after uniform instrument set-up led only to a 13% reduction of interlaboratory variability of results as compared to data analysis using local protocols. The standard protocol for instrument set-up led to uniform positioning of relatively strong FL signals but variable positioning of unstained cells on the FL histogram scales. Hence, standard FL marker settings were inappropriate for some instruments. Therefore, instrument responses to FITC and PE signals in Workshop 2 were calibrated using microbeads labeled with FITC or PE in a range of predefined FL intensities expressed in MESF units (molecules of equivalent soluble fluorochrome). That approach allowed the positioning of the FL markers for the standard analysis on the basis of identical FL1 and FL2 intensities, expressed in MESF units, for all instruments. Standard analysis of list mode data acquired after uniform instrument set-up and calibrated FL marker settings led to a 43% reduction of interlaboratory variability as compared to data analysis to local protocols. We conclude that standard list mode data analysis using fixed FL marker settings reduces the interlaboratory variability of flow cytometric results on prestained PBMC, provided that the instruments have been set up in a uniform way and that FL markers have been standardized on the basis of calibration of each instrument's response to the corresponding FL signals.

Antigens, CD↗