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PubMed1984

The implications of assaying external quality control sera under 'special conditions'.

Two identical series of Wellcome quality control specimens were analysed by different procedures. One series was entered into the laboratory in the same way as patients' specimens while the other was analysed under special favourable conditions. This involved assaying the samples in replicate in different batches, omitting transcription errors and outliers, and placing the sample in a position following a calibration standard or an internal control. It was found that a significantly higher position in overall league ranking was achieved by assaying the control under 'special conditions'.

Blood Chemical Analysis↗
PubMed1980

Economic impact of quality control in diagnostic radiology.

With ever-increasing costs confronting health care facilities, much attention is being focused on various cost-containment projects. Although it is generally assumed that a radiology department quality control program will increase costs, institutional savings may also result. A comprehensive quality control program involving continuing education, simplification of technic, processor control, standardization of cassettes, and preventive maintenance resulted in substantial savings for a medical school radiology department.

Allied Health Personnel↗
PubMed2000

Application of LCModel for quality control and quantitative in vivo 1H MR spectroscopy by short echo time STEAM sequence.

The linear combination of model spectra (LCModel) calculation of a parameter for long-term quality control, kT, was introduced, representing the ratio of the temporal and nominal intensities of CH3 groups of lactate and acetate in a quality control phantom. This procedure is a part of the quality assurance of the scanner using fully automatic measurement and calculation of kT parameters, and utilizing Shewhart regulation control charts for continuous evaluation of the magnetic resonance (MR) scanner setting. The application of the kT parameter for the correction of in vivo data increases the precision of molar concentration determination by about 4%. This was tested by the quantitative in vivo MR determination of the molar concentrations of 13 prominent metabolites (N-acetylaspartate (NAA), N-acetylaspartylglutamate, creatine and phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol, scyllo-inositol, gamma-aminobutyric acid, glutamine, glutamate, glucose, lactate, alanine, taurine) in the white matter and hippocampus of the brain in groups of volunteers, using a short echo time stimulated echo acquisition mode sequence (echo time = 10 ms) and the LCModel technique. The repeatability of the measurement of prominent metabolites such as NAA, Cr and Cho was found to be around 10% (relative standard deviation, n = 6); precision in a group of volunteers (n = 20 and 28, respectively) was in the range of approximately 13-20%. For other metabolites, which are measured with a lower signal-to-noise ratio, the precision can be much lower.

Acetates↗
PubMedDate not supplied

Freezing red blood cells prepared for quality control of antiglobulin sera.

A small-aliquot freezing technique was employed to store at -80 C red blood cells (RBC) prepared for quality control of antiglobulin sera. These RBC were used to test the specificity and potency of both polyspecific and monospecific antiglobulin sera on the day of use. Following deglycerolization, about 83 per cent of test RBC were recovered. They were then stored as 5 per cent suspensions in 0.9% NaCl at 4 C for up to two weeks and tested for specific agglutination. EIg (RBC sensitized with immunoglobulins) and EC4 (RBC sensitized with the fourth component of human complement) remained reactive for the two-week period. EC43 (RBC sensitized with both the fourth and third components of human complement) tended to lose reactivity only with anti-C3c antibodies following deglycerolization and storage. EC3d (RBC sensitized with the C3d fragment of the third component of human complement), produced in vivo as a result of Mycoplasma pneumoniae infection, remained reactive for the two-week period, whereas EC3d prepared by the alternative pathway of complement activation was useful only for one week. Use of deglycerolized test RBC improved quality-control procedures by saving materials and technician time as well as by providing a constant supply of uniformly prepared test RBC.

Complement C3↗
PubMed1993

[Study of quality control on herbal drugs and preparations of daqingye and banlangen].

This paper first suggests that 2,4 (1H,3H) quinazolinedione (QZL) may be used as a quality control standard for the Chinese herbal drugs Daqingye (Folium Strobilanthis et Polygoni) and Banlangen (Radix Strobilanthis) as well as its preparations. QZL was found for the first time from the above mentioned two Chinese herbal drugs which has a representative property. Its content is stable. This made it possible to solve the difficulty of quality control for the preparations "antipyretic and common cold granules" and "Banlangan granules" and provide a reliable assay method to evaluate the quality of the herbal preparations. By changing the wavelength and using gradient elution in HPLC, 3 constituents can be determined through one injection by the present method, thus the time of determination may be shortened and the efficiency of assay increased. The method showed good linearity (r = 0.99998, n = 4) in the range of 0.2-3.2 micrograms/ml of QZL, the average recovery was above 95% with RSD < 1.5% (n = 3). HPLC condition: Column: LiChrosorb RP 18; elution gradient: methanol from 35% to 90% in water solution; determination wavelength: 226 nm and 288 nm.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMedDate not supplied

Rapid screening of cervical smears as a method of internal quality control. For how long should we rescreen?

OBJECTIVE: To compare the effectiveness of rapid screening of cervical smears as a method of internal quality control with 10% random rescreening. STUDY DESIGN: From June 5 to July 14, 1995 (6 weeks), all consecutive cervical smears received in the department (n = 8,800) were entered into the study and were prescreened for a duration of 30 seconds (n = 2,938), 1 minute (n = 2,925) or 2 minutes (n = 2,937) over a period of 2 weeks each. RESULTS: Rapid screening of all negative and unsatisfactory smears detected more cytologic abnormalities than would be expected with 10% random rescreening. Thirty-second rapid screening of all negative and unsatisfactory smears was more efficient in detecting false negatives than screening a proportion of the smears for longer periods of time. Rapid screening was also a very effective method of detecting severe cytologic abnormalities in unscreened smears, detecting over 90% of high grade lesions. CONCLUSION: Rapid rescreening of negative and unsatisfactory cervical smears is recommended as a very effective method of internal quality control. It is superior to 10% random rescreening in reducing the false negative rate. Thirty-second rapid rescreening is the most efficient period for which smears should be screened. Rapid screening of unscreened smears could be used as a means of selecting patients for prompt referral when a laboratory backlog exists.

False Negative Reactions↗
PubMed1992

[Quality control in the allergy laboratory--4 years "Allergy Ring Trial" in Austria].

In 1988 the Austrian Society for Allergology and Immunology initiated an external quality control program for the in vitro allergy diagnosis. In 12 mailings, 62 sera from allergic patients were sent to selected laboratories in order to determine total and antigen specific IgE according to the laboratory-specific methods. The values for total IgE varied considerably (73.9% were within +/- 1 SD, 94.3% within +/- 2 SD and 99.1% within +/- 2 SD, but only 0.9% beyond that). Sources of error were mainly attributable to inappropriate equipment and low quality reagents, but also bad test performance, with respect to personnel and the routines. In contrast, antigen specific IgE against pollen, mites, moulds, insect venoms, animal danders, drugs, parasites, environmental and food antigens revealed quite homogeneous results. Out of 1492 data, only 46 (3.1%) had to be declared as "wrong", and the variability of the RAST-classes was low. Whereas the quality of the reagents from all the different suppliers was not absolutely reliable at the beginning of the study, it improved considerably with time, as consequence of our complaints. The comparability of the methods for detecting total-IgE were non-satisfactory, whereas those for antigen specific IgE were generally good. The variety of methods employed (radio- and enzyme immunologic, fluoro- and nephelometric methods, etc.) should entail appropriate consequences, especially critical comparisons within one and the same laboratory; in addition, international standardization of the "normal" values should replace company-standards, and quality control programs for each test system before it is marketed should be mandatory. Our results confirm, that external control should be obligatory for any laboratory.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗
PubMed1994

Evaluation of the PAPNET cytologic screening system for quality control of cervical smears.

The PAPNET system is an automated interactive instrument for analysis of conventional (Papanicolaou) cervical smears. The instrument, described in this paper, introduces several important innovations to cytology automation. The cell selection system is composed of two stages: an algorithmic classifier, followed by a trained neural network allowing for great flexibility and precision in recognition of abnormal cell images. Contrary to other attempts at cytology automation, this machine does not attempt to diagnose cell abnormalities. Instead, it is interactive, leaving the assessment of the cells displayed on a high-resolution video screen to trained human observers. The slides judged to contain abnormal cells or to be inadequate are referred for a second microscopic review. Two versions of the instrument (Alpha and Beta) were evaluated in several modes. Initial testing was performed on archival smears with known, histologically confirmed neoplastic lesions of the uterine cervix. These lesions comprised the entire spectrum of abnormalities, from low-grade lesions to invasive cancers of several types. The Alpha machine displayed recognizable abnormal cells in 97% of the 201 cases, and the Beta machine displayed such cells in 97.2% of 176 cases. The Beta instrument was subsequently tested on 500 sequential archival cervical smears that had been previously subjected to a rigorous quality control. One hundred forty smears (28%), which either displayed atypical cells or were considered "inadequate," were referred for further rescreening. Fifteen of 16 previously diagnosed neoplastic smears were appropriately identified with the help of the machine. The one missed case contained a single cluster of vacuolated cancer cells from an endometrial carcinoma. As a result of PAPNET-triggered review, three new cases of low-grade squamous intraepithelial lesions view, three new cases of low-grade squamous intraepithelial lesions (SIL) came to light in previously negative smears; three additional cases, previously classified as atypical, were also reclassified as SIL, for a net gain of six neoplastic abnormalities. In two additional atypical cases, colposcopic follow-up was recommended, even though the diagnosis was not modified. Two cases of cervical intraepithelial neoplasia, represented by tiny single clusters of abnormal cells missed on original screening, quality control, and on machine rescreening, came to light on second review of the residual 360 cases. The initial experience with the PAPNET system suggests that the instrument may be valuable in quality control and may assist in significantly reducing false-negative cervical smears in an efficient and timely manner. Further testing of the instrument on a much larger number of cervical smears is in progress.

Algorithms↗
PubMed1997

Quality control for industrial hygiene laboratories.

In the Republic of Korea a quality control programme has been introduced for industrial hygiene laboratories responsible for monitoring chemicals in working environments. Its development is outlined below.

Asbestos↗
PubMed1997

[Quality control in clinical testing--past and near future].

To provide clinical testing that is useful for medical treatment, it is essential to provide correct, reliable test results to doctors and patients, i.e. high-quality test data are always required for appropriate medical treatment. To fulfill this requirement, it is necessary to establish and smoothly manage a test quality control system designed to maintain a fixed level of data accuracy and precision. The history of quality control in clinical testing spans nearly 30 years and new developments and innovations are required in this field. In this memorial lecture, I will review the development of clinical laboratory testing and explore the potential for improved test result control in the near future.

Clinical Laboratory Techniques↗
PubMed1996

[Cryopreservation of erythrocytes: detailed quality control].

It has been well established that cryopreservation of red cells with glycerol is a suitable method for long-time storage. Therefore, many data for quality control have been published. Most measurements, however, are restricted to the final product. Less information is available about the particular steps of cryopreservation. The present paper describes in detail the results of quality control measurements during the procedure. Although the final product meets the demand of the WHO for cryopreserved red cells, it could be demonstrated that erythrocytes are remarkably damaged by the deep-freezing process. Further experiments seem to be necessary in order to improve the details of the deep-freezing procedure.

Blood Preservation↗
PubMed1990

Statistical quality control in nursing homes: assessment and management of chronic urinary incontinence.

This article describes a statistical quality control system that allows nurse managers to monitor staff performance of a critical patient care function. Descriptive data concerning patients' incontinence frequencies were collected during a two-day assessment period for 87 patients under conditions that guaranteed that the patients' protective garments were changed on a one- or two-hour basis. The average and expected norms of patient wetness were calculated for a sample of patients in four different nursing homes. Periodic monitoring of patient wetness in each sample and the use of statistical quality control charts permitted nurse managers to determine if nursing aides were changing patients on either a one- or a two-hour schedule. The implications of the research for meeting federal incontinence care standards and for assuring high-quality patient care are discussed.

Aged↗
PubMed1989

A new cell culture assay for quality control in IVF.

A new, simple and sensitive bioassay for quality testing in IVF is described. This bioassay (Medi-Cult Hybritest, GEA Ltd, Biotech Division, Hvidovre, Denmark) is based on the culture of the rapidly growing mouse hybridoma cell line 1E6 in a defined serum-free culture medium. The use of serum-free conditions greatly increases the sensitivity to toxic substances, due to the absence of binding proteins. The testing of known toxic agents showed that this assay disclosed cytotoxicity with a high sensitivity. The Hybritest thus provides a simple yet sensitive and reproducible bioassay for quality control of culture media, water, chemical compounds and equipment in an IVF programme. Tests of different batches of culture media showed that media for IVF should be processed from powder and high-quality sterile water. It is important not only to test the single components of the culture media, but also the final product in a sensitive test system.

Animals↗
PubMed1998

Ste6p mutants defective in exit from the endoplasmic reticulum (ER) reveal aspects of an ER quality control pathway in Saccharomyces cerevisiae.

We are studying the intracellular trafficking of the multispanning membrane protein Ste6p, the a-factor transporter in Saccharomyces cerevisiae and a member of the ATP-binding cassette superfamily of proteins. In the present study, we have used Ste6p as model for studying the process of endoplasmic reticulum (ER) quality control, about which relatively little is known in yeast. We have identified three mutant forms of Ste6p that are aberrantly ER retained, as determined by immunofluorescence and subcellular fractionation. By pulse-chase metabolic labeling, we demonstrate that these mutants define two distinct classes. The single member of Class I, Ste6-166p, is highly unstable. We show that its degradation involves the ubiquitin-proteasome system, as indicated by its in vivo stabilization in certain ubiquitin-proteasome mutants or when cells are treated with the proteasome inhibitor drug MG132. The two Class II mutant proteins, Ste6-13p and Ste6-90p, are hyperstable relative to wild-type Ste6p and accumulate in the ER membrane. This represents the first report of a single protein in yeast for which distinct mutant forms can be channeled to different outcomes by the ER quality control system. We propose that these two classes of ER-retained Ste6p mutants may define distinct checkpoint steps in a linear pathway of ER quality control in yeast. In addition, a screen for high-copy suppressors of the mating defect of one of the ER-retained ste6 mutants has identified a proteasome subunit, Hrd2p/p97, previously implicated in the regulated degradation of wild-type hydroxymethylglutaryl-CoA reductase in the ER membrane.

ATP-Binding Cassette Transporters↗
PubMed2006

[Study on the method of rapid quality control of aqueous solution of flos lonicerae japonicae extraction in the preparation of qingkailing injection].

To establish a rapid and accurate on-line quality control method for aqueous solution of Flos Lonicerae Japonicae extraction (ASFLJE) in the preparation of Qingkailing injection, the wavelength of UV original spectrum and its first derivative spectrum of ASFLJE were scanned. The most suitable spectrum type and wavelength correlated with the chlorogenic acid content in ASFLJE determined by RP-HPLC were chosen to build a regress model. The UV equation for predicting chlorogenic acid content in ASFLJE was established. Other 10 batches of ASFLJE were used for testing the on-line prediction results by comparison of the values of chlorogenic acid content determined by HPLC and predicting equation respectively. The most suitable wavelengths correlated with chlorogenic acid content were 294 nm (r = 0.991 9, n = 28) in the original UV spectrum and 316 nm (r = 0.995 9, n = 28) in the first derivative spectrum respectively. The predicting equation of chlorogenic acid content was: c(mg x mL(-1)) = 506. 254 3 x A316 nm + 0.177 1 (r = 0.995 9, n = 28). This predicting equation is credible and accurate, as tested by HPLC method (r = 0.991 5, n = 10). The prediction results of chlorogenic acid content were: the chlorogenic acid content in probable 90 percent ASFLJE was: 0.4-4.0(mg x mL(-1)). This method is rapid, simple and accurate, and can be used for the on-line quality control of ASFLJE in Qingkailing injection preparation.

Chlorogenic Acid↗
PubMed1999

[Quality control of labile blood products. Why and howto properly take a specimen? Labile Blood Products Group of the French Blood Transfusion Society].

This article reviews the various techniques of sampling used for the quality control of blood cell products. The importance of this stage for the validity of quality control results is emphasized. Three sampling methods, i.e., stripping, the sterile connection of sampling bag and the destructive method, are described in the form of operating modes and analyzed according to their advantages and drawbacks. The results of a comparative study carried out by the working group 'Blood Cell Products' of the French Society of Blood Transfusion are presented, showing that each method is valid and permits one to obtain a representative sample of the product to be controlled. Thus the diversity of the sampling methods allows us to select the one most adapted to the product to be controlled and to the analyses to be carried out afterward.

Blood Specimen Collection↗