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PubMed1998

[Organization and quality control of a clinical database on intensive care medicine in central and suburban Paris].

BACKGROUND: Epidemiology and medical care appraisal of intensive care medicine relies on the homogeneity of information systems. This work is about a collaborative database related to intensive care units in Paris and its suburb. METHODS: A college of intensivists defined a standard dataset about stays, outcomes, severity of illness, diagnoses and work load, which are collected and analysed by a data management center. A quality control of the database was performed on a random sample of 199 stays. RESULTS: In 1996, 25 intensive care units participated in the database which encompassed more than 35,000 stays. The control of data quality showed a good reliability of data about stays, severity and workload but reproducibility of diagnosis coding has to be improved by means of more accurate coding guidelines. CONCLUSION: This database of case-mix and outcome information allows comparison and medical care appraisal of intensive care units.

Critical Care↗
PubMed2000

Quality control of spirometry in the elderly. The SA.R.A. study. SAlute Respiration nell'Anziano = Respiratory Health in the Elderly.

We evaluated the outcome of the spirometry quality control program of the SA.R.A. multicenter project, the aim of which is the multidimensional assessment of asthma and COPD in the elderly (>/= 65 yr). The factors determining this quality were also evaluated. The program was based on standardized procedures (ATS recommendations), performed by specifically trained and certified personnel; a fully-computerized spirometer with customized software was used for spirometry. A reference center made monthly controls. Overall, 638 cases and 984 controls were examined. Spirometric measurements were obtained in 607 cases and 912 controls; 508 and 747 tests with at least three acceptable curves were obtained in cases and in controls, respectively (NS). The percentage of reproducible tests ranged between 95.8% for FEV(1) in controls and 87.6% for FVC in cases. The average reproducibility for FEV(1) was 61.6 ml in cases and 58.3 ml in controls (NS). Cognitive impairment, shorter 6-min walk distance, and lower educational level were found to be independent risk factors for a poorer acceptability rate (logistic regression analysis). Male sex and age were risk factors for a poorer reproducibility of FEV(1). Reproducibility tended to improve with time (p < 0.001). Although spirometry becomes increasingly difficult in aging patients, a rigorous quality control program can ensure that reliable data are obtained in the majority of patients.

Age Factors↗
PubMed2005

Design and synthesis of oligosaccharides that interfere with glycoprotein quality-control systems.

Calnexin (CNX) and its soluble homologue calreticulin (CRT) are lectin-like molecular chaperones that help newly synthesized glycoproteins to fold correctly in the rough endoplasmic reticulum (ER). To investigate the mechanism of glycoprotein-quality control, we have synthesized structurally defined high-mannose-type oligosaccharides related to this system. This paper describes the synthesis of the non-natural undecasaccharide 2 and heptasaccharide 16, designed as potential inhibitors of the ER quality-control system. Each possesses the key tetrasaccharide element (Glc1Man3) critical for the CNX/CRT binding, while lacking the pentamannosyl branch required for glucosidase II recognition. These oligosaccharides were evaluated for their ability to bind CRT by isothermal titration calorimetry (ITC). As expected, each of them had a significant affinity towards CRT. In addition, these compounds were shown to be resistant to glucosidase II digestion. Their activities in blocking the chaperone function of CRT were next measured by using malate dehydrogenase (MDH) as a substrate. Their inhibitory effects were shown to correlate well with their CRT-binding affinities, both being critically dependent upon the presence of the terminal glucose (Glc) residue.

Calnexin↗
PubMed2026

TargetQC: A targeted quality control framework for clinical genomic testing.

Reliable genetic testing depends on accurate assessment of sequencing quality in clinically relevant genomic regions that directly influence variant interpretation. We developed TargetQC, a flexible quality control framework that supports user-defined gene sets, coverage thresholds, and variant sets for evaluating sequencing performance across exome sequencing (ES) and genome sequencing (GS) platforms. TargetQC assesses exon and gene coverage, identifies regions meeting predefined coverage thresholds, evaluates variant detection accuracy, and measures sequencing quality at pathogenic variant sites. We applied TargetQC to the reference sample NA12878 and 665 clinical samples across five ES platforms and one GS platform. ES-VendorB and ES-VendorE achieved the most complete coverage of OMIM coding regions in NA12878, whereas ES-VendorD and ES-VendorE showed the highest coverage compliance in clinical samples. ES-VendorB and GS demonstrated the highest variant detection accuracy. TargetQC provides a practical framework for benchmarking sequencing performance and informing platform selection in clinical genomics.

exome sequencing↗
PubMed1989

[Regional external quality control of the analysis of urinary calculi].

Within one year's period a model for external quality control of urolithiasis was tested. This model includes specifications concerning precision as well as accuracy derived from diagnostic and therapeutic considerations. The quality indices obtained for precision QI-P and accuracy QI-R confirm that all analytical centres of urolithiasis in the GDR are to be found under the fixed specifications, partially to a considerable extent. Thus all participants indirectly demonstrated that the state of adjustment of instrumentation and thereby the reference factors remain stable for at least one year. The system being continued the specifications of precision (ST 0%) and accuracy (D0) might even be fixed more exactly from an analytical point of view.

Germany, East↗
PubMed1987

Quality control limits for microdilution susceptibility tests with norfloxacin.

A multilaboratory study was designed to define quality control limits for microdilution susceptibility tests with norfloxacin. The following limits were proposed: for Escherichia coli ATCC 25922, 0.03 to 0.125 micrograms/ml; for Pseudomonas aeruginosa ATCC 27853, 1.0 to 4.0 micrograms/ml; for Staphylococcus aureus ATCC 29213, 0.5 to 2.0 micrograms/ml; and for Streptococcus faecalis ATCC 29212, 2.0 to 8.0 micrograms/ml. The latter represents a change in the previously recommended control limits.

Enterococcus faecalis↗
PubMed1971

Quality control in routine haemoglobinometry.

An analysis of haemoglobin estimations in a routine laboratory shows that quality control methods based on mean values are unsatisfactory. The use of a cusum method together with control samples is a sensitive and convenient technique for the early discovery of minor deviations in results and it is not dependent on a stable population of patients.

Hemoglobinometry↗
PubMed2004

Personalized versus non-personalized computerized decision support system to increase therapeutic quality control of oral anticoagulant therapy: an alternating time series analysis.

BACKGROUND: The quality control of oral anticoagulant therapy (OAT) during the initiation and maintenance treatment is generally poor. Physicians' ordering of OAT (especially fluindione and warfarin) can be improved by dose adjustment algorithms, taking into account the results of International Normalized Ratio (INR). Reminders at the point of care, computerized or not, have been demonstrated to be effective in changing physicians prescription behavior.However, few studies have addressed the benefit of personalized reminders versus non personalized reminders, whereas the personalized reminders require more development to access patient record data and integrate with the computerized physician order entry system. The Hospital Information System of George Pompidou European Hospital integrates an electronic medical record, lab test and drugs order entry system. This system allows to evaluate such reminders and to consider their implementation for routine use as well as the continuous evaluation of their impact on medical practice quality indicators. The objective of this study is to evaluate the impact of two types of reminders on overtreatment by oral anticoagulant: a simple reminder of text formatted dose adjustment table and a personalized recommendation for oral anticoagulant dose and next date of INR control, adapted to patient data. Both types of reminders appear to the physician at the moment of drug ordering.

Administration, Oral↗
PubMed2005

Quality control guidelines for testing gram-negative control strains with polymyxin B and colistin (polymyxin E) by standardized methods.

An eight-laboratory study addressed the urgent need for quality control (QC) ranges for susceptibility determination when testing colistin (polymyxin E) and polymyxin B, two polycationic peptide antimicrobial agents, against multidrug-resistant gram-negative bacilli. For Escherichia coli ATCC 25922l, the QC ranges were as follows: for colistin, 0.25 to 1 microg/ml (11 to 17 mm), and for polymyxin B, 0.25 to 2 microg/ml (13 to 19 mm). For Pseudomonas aeruginosa ATCC 27853, the QC ranges were as follows: for colistin, 0.25 to 2 microg/ml (11 to 17 mm), and for polymyxin B, 0.25 to 2 mug/ml (14 to 18 mm). More than 97% of all reported QC results were within these proposed ranges.

Anti-Bacterial Agents↗
PubMed1993

Accuracy of reporting of methicillin-resistant Staphylococcus aureus in a provincial quality control program: a 9-year study.

We report the results of a province-wide quality control program in which five methicillin-resistant Staphylococcus aureus strains were circulated to all Ontario laboratories (hospital, private, and public health laboratories) on nine occasions between 1980 and 1989. The level of expression of methicillin resistance in each of the isolates was determined by performing viable colony counts on serial dilutions of methicillin in agar, and each isolate was assigned to an expression class according to previous published criteria (A. Tomasz, S. Nachman, and H. Leaf, Antimicrob. Agents Chemother. 35:124-129, 1991). Over this time there was an improvement in the performance of laboratories in the recognition of three strains that were relatively easy to detect (strains B, C, and E). These strains were of expression class II, and 98% of laboratories reported correct identifications in 1986. Performance in identifying two strains (strains A and D) of expression class I remained poor. Strain A was circulated in two surveys in 1987 and 1989, and laboratories were sent a questionnaire requesting details of the methods used in those two surveys. The methods used by the laboratories were classified into three categories: disk diffusion, single-plate screening by agar incorporation, and automated methods, which included premanufactured MIC panels. Between the 1987 and 1989 surveys, there was no change in the performance of the disk diffusion test (60% correct on both occasions), but there was improvement in the sensitivity of the agar incorporation test (36% correct in 1987 and 84% correct in 1989) and in automated methods (43% correct in 1987 and 79% correct in 1989). Over a decade, there was overall improvement in the performance of laboratories in detecting easy-to-detect strains, but there were difficulties in detecting organisms of low expression class, and an organism of very low expression class should be designated as a control organism for routine testing of methicillin-resistant s. aureus isolates.

Data Collection↗
PubMed1998

Application of an Electronic Aroma Sensing System to Cork Stopper Quality Control.

Cork odors were characterized using an electronic aroma sensing system. The electronic system is a compact, benchtop instrument comprising a sensor array, signal processing hardware, a measurement algorithm, and a pattern classification system. The sensor array responds to the presence of aroma volatile compounds by changes in their electrical properties. Resistance changes are displayed as a histogram, which is a fingerprint of the aroma being analyzed. Five different cork odors were studied: NE, which is considered as standard cork odor; CO, exhibiting the pleasant boiled cork odor (it is also considered as a good odor); PO, corresponding to rotten odor; and B and BO, representing moldy and very intensely moldy odors, respectively. This electronic aroma sensing system could discriminate quickly and objectively between acceptable odor and the unacceptable taint. Characterization and selection of a subset of sensors were performed. A relation between sensors and specific odors was established. The system, once trained with representative acceptable and unacceptable samples, could be used as a simple quality control tool and incorporated into the normal quality control procedures for each batch of product, by providing real-time analysis of a sample overall aroma.

Journal Article↗
PubMed2005

Endoplasmic reticulum-associated protein quality control and degradation: genome-wide screen for ERAD components.

In this chapter, a genetic approach is presented that leads to the isolation of mutants and to the identification of proteins involved in protein quality control and endoplasmic reticulum-associated degradation (ERAD). The method makes use of a genomic screen of a yeast deletion library (EUROSCARF). Transformation of each of the approx 5000 strains deleted in one nonvital gene each with a CPY* chimera containing CPY* C-terminally fused to a transmembrane domain and the cytosolic Leu2 protein (3-isopropylmalate dehydrogenase) constitutes the basic screening procedure. Because of a Leu2p deficiency in all deletion strains, cells can grow only when the CTL* chimera is present. As the CPY* module of CTL* will be recognized in ERAD-proficient cells, CTL* will be degraded and the strain is unable to grow. Therefore the absence of genes necessary for ER quality control and ERAD will allow cell growth and indicate the necessity of the respective gene for these processes.

3-Isopropylmalate Dehydrogenase↗
PubMed1977

Performance characteristics of rules for internal quality control: probabilities for false rejection and error detection.

When assessing the performance of an internal quality control system, it is useful to determine the probability for false rejections (pfr) and the probability for error detection (ped). These performance characteristics are estimated here by use of a computer stimulation procedure. The control rules studied include those commonly employed with Shewhart-type control charts, a cumulative sum rule, and rules applicable when a series of control measurements are treated as a single control observation. The error situations studied include an increase in random error, a systematic shift, a systematic drift, and mixtures of these. The probability for error detection is very dependent on the number of control observations and the choice of control rules. No one rule is best for detecting all errors, thus combinations of rules are desirable. Some appropriate combinations are suggested and their performance characteristics are presented.

Chemistry, Clinical↗
PubMed1980

Internal analytical quality control using the cusum chart and truncated V-mask procedure.

It is recommended that quality control data be recorded on a standard form to facilitate calculation of the cusum increments and of the cumulative sums (cusums) for plotting on the cusum chart. The 'in control' and 'out of control' judgements are made with the aid of a truncated V-mask. Full details of calculation procedures are described without recourse to statistical theory so that the cusum and truncated V-mask procedure may be carried out by operators without training in statistics.

Mathematics↗
PubMed1982

Evaluation of blood gas quality control and proficiency testing materials by tonometry.

Because of consistent differences found by other investigators and by us, we systematically tonometered, sampled, and measured PO2 and PCO2 concentrations of fresh blood, plasma, and several commercial quality control materials in three models of semiautomated blood gas machines. We found no significant differences between materials or machines for PCO2 between 25 to 72 mm Hg. For tonometered PO2 of approximately 25 to 100 mm Hg, the measured PO2 concentrations were accurate for blood, high for materials with hemoglobin or fluorocarbon (high O2 capacity), and very high for other materials (low O2 capacity). A low O2 capacity material tonometered to a PO2 of 0 mm Hg gave very high values in semiautomated machines and gave correct values only when injected repeatedly without interrupting rinse cycles into a manual machine. These findings indicate significant contamination of blood gas machines with fluids other than the sample so that low O2 capacity quality control materials are inadequate for proficiency testing at degrees of PO2 below 100 mm Hg.

Blood Gas Analysis↗
PubMed2005

[Preparation and quality control of low molecular weight chitosan].

OBJECTIVE: To prepare the low molecular weight chitosan (LMWC) and establish the method for quality control. METHOD: Use enzymatic degradation to prepare LMWC with chitosan, and separate by ultrafiltration; the molecular weight and purity were determined by gel permeation chromatography (GPC) and colorimetry respectively. RESULT: LMWC was prepared by control the hours of enzymatic degradation and ultrafiltered through filter with cutoff molecular of 10K Dalton and 50 K dalton; the average molecular weight was 20 K dalton and the purity was (96.60 +/- 1.56)%. CONCLUSION: The condition of enzymatic degradation is geniality and easy to control, LMWCs with different molecular weight can separate by ultrafiltration efficiently; the quality of LMWC can control with gel permeation chromatography (GPC) and colorimetry.

Cellulase↗
PubMed2000

[Accelerated methods for the microbiological quality control of food products in the critical control point system in the analysis of the hazard factor].

The rapid microbiological methods of quality control food in the HACCP systems. The paper contain the summary of the hazard analysis control point concept for the control of food microbiological safety. It characterises the express methods that can detect and identify the Food Poison Organisms, including the methods for the rapid detection and enumeration of microorganisms by means of a new impedance measuring systems, molecular-biologic methods and DNA-diagnostic methods.

Bacteria↗