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At least 1,477 records · Page 82Linked to original sources
PubMed1989

Quality control in an in-vitro fertilization laboratory: use of human sperm survival studies.

A bioassay procedure is described for quality control testing of various disposable items used in routine IVF procedures. This bioassay is performed over 4 days and uses the survival of human sperm in vitro at room temperature to assess which products are suitable for use. New products were tested for cytotoxicity using a general screening method and subsequent batches of every suitable item tested to detect interbatch variation. Products were considered suitable or unsuitable for use depending upon a calculated sperm survival index. Two main types of product were found to be cytotoxic, namely certain brands of syringe and surgical gloves, the common feature of both being the presence of rubber components. The bioassay was also used to investigate further the cytotoxic effect of the powdered and starch-free surgical gloves. The cytotoxic substances from both types of surgical glove were readily transferred to an embryo replacement catheter by touch, and washing of the gloves reduced this effect only moderately. The bioassay has proved inexpensive and convenient but more importantly it has been invaluable for detecting potential sources of cytotoxicity before they are introduced into a standard IVF protocol.

Cell Survival↗
PubMed2003

[Investigation and analysis of total quality control in nurses with different working levels].

OBJECTIVE: To investigate the understanding of the nurses of different levels concerning Total Quality Control (TQC). METHODS: A total of 198 nurses using stratified random sampling in proportion to the ratio of different levels of the nurses. A questionnaire with approved validity was used in the survey, and the results were statistically analyzed. RESULTS: In terms of basic knowledge of TQC, the scores of assistant nurses the lowest (P<0.05), and the responsible nurses had lower scores than head nurses and nursing officers (P<0.05), while the scores of the nurses whose length of service ranged from 3 to 10 years were lower than those of nurses who had been in service for above 10 years. In terms of TQC common methods, both assistant nurses and responsibility nurses had lower scores than nurses-in-charge, head nurses and nursing officers (P<0.05). The scores of nurses in service for less than 15 years did not significantly differ, but were obviously lower than those of nurses in service for over 15 years. There was no significant difference between the scores of nurses with different academic degrees. CONCLUSION: The TQC knowledge of the nurses are different based on their working levels and length of service.

Adult↗
PubMed1998

Evaluation of GHb assays in France by national quality control surveys.

OBJECTIVE: To evaluate the state of the art concerning GHb assays through analysis of a large-scale quality control survey and to compare the results with those of previous surveys. RESEARCH DESIGN AND METHODS: A lyophilized hemolyzate prepared from human erythrocytes containing a physiological HbA1c level (5.5%) was sent to 3,500 French laboratories in February of 1995 and assayed as a patient's sample under routine conditions. Distribution of values was analyzed from the reported results for each method. The results were compared with the assigned value (acceptable range: +/- 20%) and with the upper value of the reference range currently used. RESULTS: Results were obtained from 2,674 laboratories, among which 39% used cation-exchange chromatography methods, 37.5% affinity chromatography, 16% immunological methods, and 7.5% electrophoresis. The number of laboratories using immunological methods increased from 100 to 400 between 1993 and 1995. The overall interlaboratory coefficient of variation (CV) was 20.2%, with within-method CVs ranging between 3.2 and 29.5%. Method-to-method accuracy varied dramatically, with mean HbA1c values ranging from 4.4 to 8.2%. Results from 75% of the laboratories were comprised in the acceptable range; 88% of them reported a value within the normal range of the method used. CONCLUSIONS: The interlaboratory variability of results illustrates the difficulties encountered by diabetologists in the follow-up of diabetic patients using results obtained from different laboratories. It demonstrates the usefulness of the internationally developed standardization process of GHb measurements and points out the need for laboratories to fulfill good practices.

Data Collection↗
PubMed2005

Effect of uncertainty components such as recalibration on the performance of quality control charts.

BACKGROUND: Uncertainty components (recalibration, new reagent lots, etc.) may be the source of random changes in the level of quality control (QC) values, thus causing false alarms. We propose a method for reducing false alarms. MATERIAL AND METHODS: Daily QC measurements of 22 biochemical quantities were recorded over 5 months, while methods and analyser showed no signs of malfunctioning. Each time series of QC values was subdivided according to reagent lot, electrolyte diluent or disposable electrode used. Analysis of variance (ANOVA) was used to examine whether mean levels changed significantly between subseries. For each quantity, the entire time series and each subseries were examined for autocorrelation. An X chart and an exponentially weighted moving average (EWMA) chart (or EWMAST [EWMA for stationary processes] in autocorrelated series) were calculated from the first 50 values of each series or subseries and applied to the whole series. Values falling outside the three standard deviation control limits were noted. RESULTS: In 22 out of 24 time series, the mean level differed significantly between subseries. These changes caused spurious autocorrelation. However, in 51.3 % of all subseries a significant autocorrelation could also be demonstrated. In total, 5.6 % and 29.1 % of all time series values fell outside the control limits of the X charts and the EWMA or EWMAST charts, respectively. These percentages were significantly reduced to 0.44 and 0.70 when the subseries-specific control charts were used. CONCLUSIONS: The mean level may change because of recalibrations or change of electrolyte diluent lot with subsequent false alarms. False alarms may be significantly reduced by revising QC charts when significant changes occur.

Albumins↗
PubMed2003

Determination of disk diffusion and MIC quality control parameters for AZD2563, a novel long-acting oxazolidinone.

AZD2563 is a new, long-acting oxazolidinone that possesses potent antimicrobial activity against Gram-positive organisms. This report summarizes the results of broth microdilution MIC and disk diffusion quality control (QC) investigations for AZD2563. All tests or methods (M2-A7 and M7-A5) and QC study designs (M23-A2) were those published by the National Committee for Clinical Laboratory Standards. QC strains tested against AZD2563 included: Staphylococcus aureus ATCC 25923 and ATCC 29213, Enterococcus faecalis ATCC 29212 and Streptococcus pneumoniae ATCC 49619. In the eight-center QC trial, 320 and 480 results were generated for MIC and disk diffusion tests, respectively. The selected 7-mm ranges for the two disk diffusion QC organisms contained > or = 98.5% of reported results. Proposed 3 or 4 log(2) dilution MIC ranges contained all reported participant results. AZD2563 disk diffusion zone diameters were generally 2-3 mm smaller than the corresponding linezolid zone diameters. In conclusion, QC ranges for AZD2563 MIC and disk diffusion methods were established and appear acceptable in preparation for the clinical trials use.

Diffusion↗
PubMed2004

Quality control guidelines for BAL9141 (Ro 63-9141), an investigational cephalosporin, when reference MIC and standardized disk diffusion susceptibility test methods are used.

BAL9141 is a novel cephalosporin with a broad spectrum of activity, including activity against methicillin-resistant staphylococci. This multicenter study was performed to establish quality control (QC) guidelines for susceptibility testing of BAL9141 in phase 3 clinical trials and after U.S. Food and Drug Administration approval. The proposed 3 or 4 log(2) dilution MIC ranges encompass 97.8 to 100.0% of reported results, while the proposed 7- to 9-mm-zone-diameter QC ranges included 95.2 to 99.4% of the participant-reported disk diffusion results.

Cephalosporins↗
PubMed1990

Quality control in planning and operating the laboratory component for the Third National Health and Nutrition Examination Survey.

Successfully acquiring high-quality laboratory data for a long-term nutrition survey such as the Third National Health and Nutrition Examination Survey (NHANES III) requires rigorous quality-control procedures throughout the entire design and implementation of the laboratory component. We discuss selection of nutritional biochemistry analyses, proper specimen collection, and the critical need for continuity of protocol during the entire survey. The NHANES III laboratory procedures are described, including specimen collection, processing, shipment to laboratories, and analyses.

Blood Chemical Analysis↗
PubMedDate not supplied

[A new sterile generator of Tc 99m. Quality control].

Production has started on a new Tc 99m sterile generator in Italy. We give the results of a series of quality controls in order to have a first evaluation of the product. The elution profile and the volume, activity, pH, aluminium concentration, 99 Mo content and radiochemical purity of the eluate were examined. Radiochemical purity tests were also carried out with some of the more widely used "in vivo" radiopharmaceuticals. The results are in line with the Official Pharmacopeia and good technical standards.

Italy↗
PubMed2001

For and against a European quality control of training.

In a world of medicine that evolves more and more rapidly, sufficient quality of education in the arts and crafts of our discipline and control of this quality are essential for the progress and vitality of Ob/Gyn. There are variations in training within European countries but with the aim of harmonization in training programmes and the flexibility of quality control mechanisms we will meet our objective that is the high standards in the care of woman throughout Europe.

Europe↗
PubMed1992

Production, quality control and characterization of an inactivated hepatitis A vaccine.

The isolation and adaptation of hepatitis A virus to cell culture opened the way to the development of vaccines. Based on experience with inactivated poliovaccines, a similar approach was chosen for the development of an inactivated hepatitis A vaccine. Strain HM175, adapted to MRC-5 human diploid cells, was used as the virus strain. Vaccine production starts with growth and multiplication of the seed virus in MRC-5 cells. The harvests are clarified, purified and concentrated. Inactivation by formaldehyde is carried out on a pool of purified harvests. Close control of all process parameters results in consistent production of completely inactivated and highly immunogenic vaccine lots. Quality control testing is based on the general requirements for biologicals of WHO and National Control Authorities. Tests have been developed and validated to show the purity of the cell substrate used for each production cycle, the quality of the virus harvest, the adequacy of the purification and inactivation processes, and the conformity to stringent specifications for purity, safety and potency of the final bulk vaccine filled in final containers. The vaccine is characterized by adequate identity tests, by its reaction with polyclonal and monoclonal antibodies, by its immunogenicity in laboratory animals and by the detailed study of the immune response in primates and human volunteers. The final result of the development of adequate production and testing methods, confirmed by extensive characterization studies, is the availability of a consistent, safe and potent hepatitis A vaccine.

Cell Line↗
PubMed1990

[Quality control and optimization of therapeutic activity with the use of thermoanalytic methods].

Thermogravimetry, differential scanning calorimetry, thermomicroscopy, transparency measure permit drug quality control: knowledge of solvated or unsolvated mole, thermal stability, identification of crystalline form (polymorphism) quick determination of total impurity with graphs. These methods can be used for therapeutic activity optimization of very weakly soluble drugs: research of the polymorph showing the best kinetic dissolution, establishment of phase diagram drug/inert substance by example for determination invariant composition particularly eutectic for which the drug solubility is increased.

Calorimetry, Differential Scanning↗
PubMed1993

Comparison of quality-control rules used in clinical chemistry laboratories.

Numerous papers have been written to show which combinations of Shewhart-type quality-control charts are optimal for detecting systematic shifts in the mean response of a process, increases in the random error of a process, and linear drift effects in the mean response across the assay batch. One paper by Westgard et al. (Clin Chem 1977;23:1857-67) especially seems to have attracted the attention of users. Here we derive detailed results that enable the characteristics of the various Shewhart-type control schemes, including the multirule scheme (Clin Chem 1981;27:493-501), to be calculated and show that a fundamental formula proposed by Westgard et al. in the earlier paper is in error, although their derived results are not seriously wrong. We also show that, from a practical point of view, a suitably chosen Cusum scheme is near optimal for all the types and combinations of errors discussed, thereby removing the selection problem for the user.

Chemistry, Clinical↗
PubMed1999

A human mitochondrial DNA standard reference material for quality control in forensic identification, medical diagnosis, and mutation detection.

A human mitochondrial DNA (mtDNA) standard reference material (SRM 2392) will provide quality control when mtDNA is sequenced for forensic identifications, medical diagnosis, or mutation detection. SRM 2392 includes DNA from two lymphoblast cell cultures (CHR and 9947A) and cloned DNA from the CHR HV1 region, which contains a C stretch and is difficult to sequence. The mtDNA sequence (but not the DNA) of a third human template GM03798 is provided for comparison. Fifty-eight unique primer sets allow any area or the entire mtDNA (16,569 bp) to be amplified and sequenced. While none of the differences in these three templates correspond to published mutations associated with specific diseases, some of these differences did result in animo acid changes compared with that published by S. Anderson et al. (1981, Nature 290: 457-465). An interlaboratory evaluation of the amplification, sequencing, and data analysis of the CHR template was conducted by four laboratories. Corroboration of the SRM results will provide quality assurance that any unknown mtDNA is also being amplified and sequenced correctly.

Cell Line↗
PubMed1988

Quality controlling interpretive reporting systems in clinical medicine--a changing responsibility.

This paper presents some observations on a number of topics which affect the quality of computer software and includes: current trends in software design, current levels of responsibilities for the various parties involved in bringing automation to clinical medicine, why software development is so difficult to quality control, and certain characteristics of system development which contribute most to the construction of inaccurate models.

Humans↗
PubMed1989

Quality control of 99mTc-labeled dextran for lymphoscintigraphy.

99mTc-labeled dextran has been suggested as a lymphoscintigraphic agent. However, quality-control results from previous studies have been controversial. In this study, the optimal concentration of stannous ion and pH value were determined to obtain maximal labeling. Paper and thin-layer chromatography showed total labeling efficiency as high as 98.4%. Anthrone test of the supernatant of the segments from thin-layer chromatographic strip was performed. Colorimetric determinations verified that dextran was found in the same locations as the peak radioactivity.

Chromatography, Paper↗
PubMed2003

Revision of linezolid disk diffusion quality control guidelines for testing Staphylococcus aureus ATCC 25923: an independent seven-laboratory trial.

The accuracy of the published disk diffusion quality control (QC) range for linezolid for Staphylococcus aureus ATCC 25923 has been reported to be problematic, prompting a multicenter study to determine if revision was necessary. Five out of seven laboratories reported values outside the current QC range. Three participants had significant (13.3-60.0%) 'unacceptable' results with zones smaller than the established range. Overall, a range of 21-32 mm was shown (82.4% within the NCCLS published range). A revision (25-31 mm; 95.7% of results) of the QC range is necessary when testing S. aureus ATCC 25923 against linezolid.

Acetamides↗
PubMed1982

Emulsions of perfluorinated compounds for use in quality control of blood gas analyses.

We prepared emulsions of perfluorinated compounds and examined their utility as liquid matrixes for tonometry in quality control of blood pH and gas analyses. Emulsions of perfluorotributylamine and perfluorodecalin, prepared by sonication, consisted largely of particles not exceeding 0.2 micrometer in diameter. Unlike most aqueous solutions these materials were not easily contaminated by room air and can be reliably used for tonometry liquids. Results for pCO2 and pO2 agreed well with calculated values. Average day-to-day coefficients of variation for emulsions of perfluorotributylamine were 2.9% for pH (within the range 7.11-7.60), 4.4% for pCO2 (2.88-9.17 kPa), and 1.6% for pO2 (7.76-40.67 kPa).

Blood Gas Analysis↗