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PubMed1990

Selection of medically useful quality-control procedures for individual tests done in a multitest analytical system.

Quality-control (QC) procedures (i.e., decision rules used, numbers of control measurements collected per run) have been selected for individual tests of a multitest analyzer, to see that clinical or "medical usefulness" requirements for quality are met. The approach for designing appropriate QC procedures includes the following steps: (a) defining requirements for quality in the form of the "total allowable analytical error" for each test, (b) determining the imprecision of each measurement procedure, (c) calculating the medically important systematic and random errors for each test, and (d) assessing the probabilities for error detection and false rejection for candidate control procedures. In applying this approach to the Hitachi 737 analyzer, a design objective of 90% (or greater) detection of systematic errors was met for most tests (sodium, potassium, glucose, urea nitrogen, creatinine, phosphorus, uric acid, cholesterol, total protein, total bilirubin, gamma-glutamyltransferase, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase) by use of 3.5s control limits with two control measurements per run (N). For the remaining tests (albumin, chloride, total CO2, calcium), requirements for QC procedures were more stringent, and 2.5s limits (with N = 2) were selected.

Autoanalysis↗
PubMed2003

Re-evaluation of quality control guidelines for gatifloxacin and garenoxacin (BMS284756) when susceptibility testing Haemophilus influenzae and Streptococcus pneumoniae.

An eight laboratory M23-A2 quality control (QC) study was performed for the re-evaluation of gatifloxacin, a new fluoroquinolone, using disk diffusion tests against Streptococcus pneumoniae ATCC 49619. The study also re-evaluated garenoxacin, a novel investigational des-F(6)-quinolone, using disk diffusion tests against S. pneumoniae ATCC 49619 and broth MIC for Hemophilus influenzae ATCC 49247. The gatifloxacin zone diameter results for S. pneumoniae did not indicate a need for QC range modification (26-34 mm; 98.3% of results); however, the garenoxacin zone diameters did demonstrate a need for a minor modification (1 mm; 26-34 mm; 96.3% of reported results). The broth MIC results for H. influenzae showed that 83.1% of the results were at the upper limit of the current range (0.008 microg/ml) published by the National Committee for Clinical Laboratory Standards (NCCLS). The proposed correction could either be 0.002-0.015 microg/mlor 0.004-0.015 microg/ml, each encompassing 100.0% of reported results (prior and current studies). All MIC results for control drugs, levofloxacin and moxifloxacin (disks) or gatifloxacin and clarithromycin (MIC), were within published NCCLS ranges.

Anti-Infective Agents↗
PubMed2005

Doelan: a solution for quality control monitoring of microarray production.

SUMMARY: Doelan is an automated tool designed to monitor the quality of DNA microarray production. The software executes a series of quality control tests on hybridizations to validate batches of chips. The reports generated by Doelan should help microarray platforms aiming at quality labels, such as ISO 9001 certification. The Doelan application is written in Java and works with a plug-in system that allows everyone to add custom validation tests. AVAILABILITY: The Doelan application is distributed under the GNU General Public License at http://transcriptome.ens.fr/doelan/

Algorithms↗
PubMed2005

Fingerprinting techniques as tools towards molecular quality control of Pseudozyma flocculosa.

In an effort to meet the stringent requirements towards registration of microorganisms as biopesticides, several molecular techniques were tested as part of a strategy to develop a quality control system for Pseudozyma flocculosa, the active ingredient of Sporodex, a biofungicide used for the control of powdery mildew fungi. In the first approach, multiplex PCR fingerprints generated by three sets of primers allowed differentiation of several isolates of P. flocculosa from closely related species, or genera such as Tilletiopsis. The same set of primers was used in quality control experiments and revealed fungal contamination that was otherwise not observed by standard culture and microscopy techniques. In addition, the use of random amplified microsatellites generated by (GT)n and (CCA)n primers was applied as a measure of possible genetic variation over 65 repeated subcultures of P. flocculosa. Finally, a novel technique was developed and named reverse intron PCR (RIP), based on the presence of an intron revealed by partial sequencing of mtLSU of P. flocculosa. RIP allowed not only differentiation of P. flocculosa from other species but also separated the isolates of different origins within P. flocculosa. This new technique could find useful applications in phylogenetic studies of closely related fungal species and isolates.

DNA Primers↗
PubMed1995

[External quality control of the parasitological diagnosis of Cryptosporidium parvum].

Between 1991 and 1994, eight external quality assessments of Cryptosporidium parvum infection diagnosis were performed. Stool specimens were sent to 74 laboratories, to be stained and examined. In 40 laboratories (54.1%), the diagnosis was correct in all evaluations, whereas in 34 (46%), the diagnosis disagreed with the parasitology reference laboratory in one occasion or more. The mean correlation of diagnoses with the reference laboratory was 88% (range 79-96%). Ninety-three percent of negative samples and 87% of positive samples were correctly diagnosed. These figures are similar to those obtained abroad. These results lead to the development of a quality control network for the diagnosis of Cryptosporidium parvum infections along the country, aiming to improve its reliability.

Animals↗
PubMed2006

Lessons learned from a sperm morphology quality control programme.

Although sperm morphology is the sperm parameter that is consistently correlated with in vitro and in vivo fertilisation, its value is often challenged due to discrepancies in reports. As sperm morphology is subjectively evaluated, the outcome of the report is entirely based on the experience and technical skill of the laboratory technician responsible for semen analyses. The study aimed to record the value of quarterly monitoring and refresher courses on morphology reading skills of technicians over a period of 40 months. Nineteen individuals from 12 different andrology laboratories were enrolled to a sperm morphology quality control programme after initial training sessions. Five of the 19 participants attended annual refresher courses. Two limits of error, namely +/- 0.5 SD and +/- 0.2 SD scores, were used to record technician deviation from the reference laboratory. Fifteen of the 19 individuals (78%) consistently reported sperm morphology readings that were within the +/- 0.5 SD limits of error. Furthermore, five of the participants, who attended annual refresher training courses, consistently reported results that were within the +/- 0.2 SD limits of error. For the first time, it has been illustrated that excellent sperm morphology reading skills can be achieved and maintained by initial training sessions, followed up with a continuous external quality control programme and annual refresher courses.

Education↗
PubMed2005

Interlaboratory comparison and accreditation in quality control testing of diagnostic X-ray equipment.

The University of Tartu provides a quality control service to the majority of diagnostic X-ray departments in Estonia. Its methodology has been adopted from the IEC and other relevant standards. Recently the Testing Centre of the University of Tartu was accredited on this methodology by ISO/IEC 17025. Besides the implementation of the quality management system, participation in interlaboratory comparison (ILC) was one of the prerequisites for the accreditation. Tests for estimating reproducibility of tube voltage and dose rate, accuracy of the voltage and accuracy of exposure time were carried out on a diagnostic X-ray unit in the Radiation and Nuclear Safety Authority in Helsinki. The measurement performance was judged by calculating deviation E(n) normalised with respect to the stated uncertainties. E(n) values for all tests were less than unity and by the common ILC criteria the testing performance could be considered as acceptable.

Accreditation↗
PubMedDate not supplied

Quality control of laboratory methods for semen evaluation in a multicenter research study.

Rigorously standardized laboratory protocols and strict quality control (QC) are essential for meaningful comparisons between semen quality data from multiple sites. We describe our experience with the Study for Future Families (SFF), a multicenter study of semen quality in the United States. Detailed protocols were developed, and technicians from each study site attended a training session at the central laboratory. Technicians received blinded replicates from diluted semen specimens for counting by MicroCell and hemacytometer. Sperm motility was assessed using videotaped recordings for simple percent motility and categorical assessment of individual sperm progression as recommended by the World Health Organization (WHO). The mean intertechnician coefficient of variation for individual specimens was 12.6% for MicroCell counts, 15.2% for hemacytometer counts, and 10.5% for percent motility. Intratechnician coefficients of variation averaged 10.3% for MicroCell counts, 12.5% for hemacytometer counts, and 5.2% for percent motility. The average percent differences between the technicians' values and the central standard for individual specimens were 13.5%, 16.6%, and 11.9% for MicroCell counts, hemacytometer counts, and simple percent motility, respectively. We achieved our goal of maintaining mean intratechnician coefficients of variation and mean percent differences from the standard values of 15% or less for measurements of simple percent motility and sperm concentration by MicroCell. Standardization using the Improved Neubauer hemacytometer chamber proved more difficult. We were not successful in standardizing a method for categorical assessment of individual sperm progression.

Biomedical Research↗
PubMed1990

Apolipoprotein assays: standardization and quality control.

A correct approach to standardization, accuracy-based methods, and well-defined quality assurance programs is indispensable for the definition of international reference intervals of apo A-I and apo B. Variability in the immunochemical determination of apo A-I and apo B can be due to both preanalytical and analytical variations, and standardized laboratories should evaluate and minimize each source of error in determining the reference intervals. A key requirement to reduce the variation between measurement techniques is the use of a common protocol for the calibration of the different methods. The basis of a calibration system is the primary standard with the absolute mass accurately determined. The primary standard is indispensable in assigning an accurate target value to reference materials with a reference method in which the primary standard immunochemically reacts the same as the protein in plasma. The reference material, which must behave immunochemically the same as the patient's sample in all methods, is then used to assign a target value to the calibrator in each method and system. Following this procedure, all assay results can be traced back to the primary standard via the serum reference material. The development and distribution of reference and quality control materials, which do not exhibit matrix effects between methods, is fundamental for the standardization process.

Apolipoprotein A-I↗
PubMed2001

Characterization and quality control of recombinant adenovirus vectors for gene therapy.

Highly purified recombinant adenovirus undergoes routine quality controls for identity, potency and purity prior to its use as a gene therapy vector. Quantitative characterization of infectivity is measurable by the expression of the DNA binding protein, an early adenoviral protein, in an immunofluorescence bioassay on permissive cells as a potency determinant. The specific particle count, a key quality indicator, is the total number of intact particles present compared to the number of infectious units. Electron microscopic analysis using negative staining gives a qualitative biophysical analysis of the particles eluted from anion-exchange HPLC. One purity assessment is accomplished via the documented presence and relative ratios of component adenoviral proteins as well as potential contaminants by reversed-phase HPLC of the intact virus followed by protein peak identification using MALDI-TOF mass spectrometry and subsequent data mining. Verification of the viral genome is performed and expression of the transgene is evaluated in in vitro systems for identity. Production lots are also evaluated for replication-competent adenovirus prior to human use. For adenovirus carrying the human IL-2 transgene, quantitative IL-2 expression is demonstrated by ELISA and cytokine potency by cytotoxic T lymphocyte assay following infection of permissive cells. Both quantitative and qualitative analyses show good batch to batch reproducibility under routine test conditions using validated methods.

Adenoviridae↗
PubMed1978

HACCP models for quality control of entrée production in hospital foodservice systems. I. Development of hazard analysis critical control point models.

HACCP models were developed as part of a research project for quality control of entrée production in three types of hospital foodservice systems: Conventional, cook/chill, and cook/freeze. Critical control points at process stages were identified. Time-temperature was a critical control point throughout entrée production in each model; time-temperature parameters were established for critical control points. Equipment sanitation and personnel sanitation are critical control points for which standards must be established by each foodservice system. Determination of the effectiveness of control measures included continuous monitoring of critical control points for time-temperature. Sanitation of equipment and personnel should be monitored using standards established by the foodservice system.

Cooking↗
PubMed2003

SecA-dependent quality control of intracellular protein localization.

Complex secretion machineries mediate protein translocation across cellular membranes. These machines typically recognize their substrates via signal sequences, which are required for proper targeting to the translocon. We report that during posttranslational secretion the widely conserved targeting factor SecA performs a quality-control function that is based on a general chaperone activity. This quality-control mechanism involves assisted folding of signal sequenceless proteins, thereby excluding them from the secretion process. These results suggest that SecA channels proteins into one of two key pathways, posttranslational secretion or folding in the cytoplasm. Implications of this finding for intracellular protein localization are discussed.

Adenosine Triphosphatases↗
PubMed2000

System performance and variability of chromatographic techniques used in pharmaceutical quality control.

Data representing the routine performance of different chromatographic equipment systems used in pharmaceutical quality control are presented. These performance data allow one to predict long-term relative uncertainties and confidence intervals for different chromatographic procedures and techniques. From the variability that is to be expected, it is apparent that many chromatographic procedures run as routine applications in the pharmaceutical industry are unlikely to be capable of controlling the tight specification limits like those usually demanded for bulk drug substances (active pharmaceutical ingredients), the European 95-105% expectation for finished drugs, or to be used in stability studies.

Chromatography, High Pressure Liquid↗
PubMed1998

[A method for auditing medical records quality: audit of 467 medical records within the framework of the medical information systems project quality control].

Future hospital accreditation could take into account the quality of medical files. The objectives of this study is to test a method for auditing and evaluating the quality of the handing of medical files. We conducted a retrospective regional audit based on the frame of reference the National Agency for Medical Development and Evaluation, by using a sample of cases, stratified by establishment. In our region, the global budgets of 47 public and private hospitals participating in the public hospital service, are adjusted while keeping in mind the medicalised activity data (PMSI). This audit was proposed to the doctors of the Department of Medical Information on the occasion of the regulatory PMSI quality control. A total of 467 questionnaires were given by 39 of the 47 sollicited hospitals (83%). The methodological aspects (questionnaire, cooperative approach...) are discussed. The make-up of medical files can alos be improved by raising the percentage of the presence of important data or documents such as the reason for admission (74.1%), the surgery report (83.2%), and the hospitalisation report (66.6%). A system for classifying the paraclinical results is shared and systematic throughout the service or hospital in only 73.2% of cases. The quality of the handing of medical files seems problematic in our hospitals and actions for improving the quality should be undertaken as a priority.

Accreditation↗
PubMed2001

Three Rs potential in the development and quality control of pharmaceuticals.

The intention of a pharmaceutical company is to develop new, efficient products quick and with a minimum of costs. Compared to in vitro methods, animal experiments in general consume much more time and resources (costs as well as time to the market) than in vitro methods. Therefore, the use of whole animal models depends primarily on the judgement of their efficacy in the screening process, but the willingness to incorporate in vitro methods in general is high and is furthered by new developments such as high-throughput screening. Nevertheless, in vitro tests might be politically promoted by increasing their costs (quality controls, requested housing conditions) and duration (time to start of an experiment, sequential performance). Which models are favoured by industry to include them in a screening process: They have to be based on our most recent understanding of the respective disease, well characterised to allow interpretation of results and require only limited development time. All these aspects argue in favour of collaboration between industry and academia, where our understanding of pathophysiology is generated and mechanism based models are developed and characterised. However, technology transfer towards industry represents a bottle-neck for industrial use of these new in vitro models. New platforms to promote this transfer should be developed in order to bring together developer and user of novel in vitro systems and promote demonstration projects. Financing of such collaborations is not the key problem (the development of a single drug makes up to 500 million $) but the dilemma of publication of results: The development advantage compared to competitors depends on the exclusive use of novel models. The protection of intellectual property rights and the public interest in spreading alternatives to animal experiments must be balanced, e.g. by delayed but indispensable publication or advantages for companies employing alternatives in the regulatory approval process for a new drug. Quality control of therapeutic drugs (except hormones and blood products) represents a minor field of animal consumption with the exception of pyrogenicity testing. Despite considerable progress due to the introduction of the Limulus assay which represents the most successful in vitro alternative in use so far. However, some limitations of this in vitro test might be overcome in the near future by the currently validated human whole blood assay. During the last few years considerable progress has been made in the replacement (and deletion) of animal tests required for the potency and safety testing of hormones. This has been made possible by biotechnical production methods, by better-defined products, and because physico-chemical methods can be used for the potency testing of these products. In general, the better defined a drug is, the easier chemical, physical or in vitro techniques can be used for batch control. Control authorities should therefore urge the use of highly standardised components.

Animal Testing Alternatives↗
PubMed2005

Predictive utility of the attached segment in the quality control of a cord blood graft.

The limited number of progenitor stem cells in umbilical cord blood (UCB) enforces the optimization and strict control of all the procedures involved in its therapeutic use--ie, collection, processing, cryopreservation, thawing, and transportation--to ensure graft potency at transplantation. For this reason, international UCB standards recommend storage of a cell sample attached to the UCB unit as a quantitative and functional control of the unit selected for transplantation. To validate the use of the sample attached to the UCB unit as a quality-control tool for the final product, UCB units (n = 20) stored in liquid nitrogen with the Bioarchive system were analyzed. The UCB units and their attached segments were thawed, and the number and viability of total nucleated cells, mononucleated cells, CD45 + cells, and CD34+ cells were determined, as were colony-forming cell counts. There was no significant difference between UCB units and segments for any of the parameters assessed. Additionally, the linear correlation coefficient (R2) in these paired samples was 0.85 and 0.78 for CD34+ cells and colony-forming cells, respectively. In conclusion, the cell sample in the tube segment physically linked to the transplant UCB bag predicts the total cell content and functionality of the unit and may serve as a source for final quality control of the UCB unit before transplantation.

Blood Cell Count↗
PubMed1977

[The use of primate tissue homogenates for quality control in the creatine kinase-MB determination with inhibiting antibodies (author's transl)].

The creatine kinase isoenzymes CK-MM, CK-MB and CK-BB from Rhesus monkey heart and brain tissue homogenates were separated chromatographically. Thereafter it could be demonstrated that the activity of the simian subunit CK-M is completely inhibited by anti-inhibitory-CK-M serum. Thus control sera from simian tissue are in principle suited for quality control in an immunological determination of creatine kinase-MB. The intra-assay variance and interassay variance were n = 56, -/x = 29.2 U/1, SD = 3.2 U/1, CV = 11.1% and n= 12, -/x = 166.7 U/1, SD = 5.0 U/1, CV = 3.0% respectively. It is desirable to develop control sera with catalytic concentrations of creatine kinase-MB in a lower range.

Animals↗
PubMed1987

Internal quality control in clinical chemistry: a teaching review.

This survey introduces the subject of internal quality assessment from a historical point of view, presents a unified approach to notation, concepts and definitions, and describes briefly those quality control procedures that are used most commonly in clinical chemistry. It is not the aim of this report to comment on all the individual contributions made in this field, but rather to concentrate on the principles. Particular emphasis is centered around assessment criteria to compare the efficiencies of selected control procedures for monitoring analyte concentrations in biological fluids. The question of whether to compare control schemes by means of average run lengths, run length distribution functions or average cost functions is considered. A rationalized approach based on the comparison of optimal procedures, using average run length, is adopted.

Chemistry, Clinical↗