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At least 235 records · Page 13Linked to original sources
PubMed1996

Quality assurance in nuclear medicine--biological quality control of radiopharmaceuticals.

Quality assurance is the sum of all parameters concerning the preparation and control of a finished product. It is a wide term commonly used for the confirmation and validity of various ways and measurements adopted to obtain a high quality procedure for intended use with guaranteed performance. Biological quality control of pharmaceutical products becomes essential as they are ultimately to be consumed by living organisms, in particular the humans. In this review, we have discussed the importance and significance of biological quality control in nuclear medicine. The current and new procedures for sterility, apyrogenecity and the biodistribution quality control, have been discussed and evaluated in view of the future needs and modern trends in this important area of research.

Journal Article↗
PubMed1978

HACCP models for quality control of entrée production in hospital foodservice systems. II. Quality assessment of beef loaves utilizing HACCP models.

HACCP models were developed for quality control of entrée production in three hospital foodservice systems: Conventional, cook/chill, and cook/freeze (1). The three systems were stimulated in a laboratory to evaluate the effectiveness of the HACCP models for quality control and to generate quantitative data for evaluating and comparing the quality of beef loaves produced under controlled conditions. Attributes measured were weight (yield) and microbiologic, nutritional, and sensory qualities. The only significant difference in the beef loaves among systems was sensory quality. Scores for overall acceptability of beef loaves in the conventional system were significantly greater (P less than 0.05) than for those of the cook/chill and cook/freeze systems. The HACCP models were effective quality control tools for entrée production; implementation of the HACCP system is recommended for hospital foodservices. The importance of the time-temperature critical point for monitoring control points in hospital foodservice systems is emphasized.

Animals↗
PubMed1997

[Quality control in ultrasonography].

Because of the lack of resources, which is getting more and more important, the control of quality is becoming an important consideration in the health system. The ultrasound as a cheap and easily available tool is no exception in this consideration. The control of the technical quality must follow certain considerations, which must be anchored in the daily usage. This is especially important if we want to evaluate the effect of the ultrasound diagnostic on the further development of the patient, the general health status, the quality of life of a certain population with large-scale epidemiologic studies. If the interpretation and indication of ultrasound should be part of medical knowledge and training, the technical quality control should also be part of the basic duties regularly done. The technical quality is the first part of the chain of the diagnostic by ultrasound. The slightest disturbance will certainly have consequences in the following steps of the treatment of the patient. The evaluation of the quality must contain a control of the security of the technical equipment available, of the spatial and contrast resolution of all the ultrasound transducers as well as a control of the monitor. Testing of the resolution can be done with a specially designed simulator/phantom, equipped with special marks permitting the measuring of the axial, lateral and transversal resolution, this simulator is also used in planimetry to evaluate the region of the optimal resolution and the geometrical reproduction. These controls must be done regularly, and the data received must be stored. Only with such a regular control we can guarantee the quality of the technical equipment and installations.

Humans↗
PubMedDate not supplied

[Good practices in clinical trials. Quality control of biological trials in hospital laboratory].

All along clinical studies of a new drug, during the second, third, or fourth phase, the hospital laboratory occurs in the biological tolerance supervision. Therefore, it calls on a number of quality controls, either voluntary or obligatory: patient identity control, analytical quality controls: between and within laboratory, regional and national controls, biological quality control. Beside these quality controls, that are necessary at the same time for clinical studies and for routine analysis, biological laboratories are submitted on norms of material, area, and employees qualification (Law of July 11th 1975).

Biological Assay↗
PubMed1997

[Current problems in quality control (QC) in hematology].

Total quality control (TQC) is one of the most important issues in laboratory hematology. As for complete blood count (CBC), almost all blood cell counters possesses quality control (QC) programs for its determination, and values of high quality can be provided by the counters. Reticulocytes can be determined precisely as well. However, mean cell volume (MCV) were slightly different among blood cell counters when semifixed QC materials were used for its surveillance. No QC materials to evaluate white cell differential functions have not be found for the common use now. Thus, urgent matter would be the development of appropriate QC materials to be used for overall blood cell counters. In coagulation testings, trials for common use of international normalized ratio (INR) for the prothrombin time (PT) test has been continued yearly due to the varieties of biophysical characteristics among PT reagents. Similar variation are also present among activated partial thromboplastin time (APTT) reagents. Some improvement would be required.

Blood Cell Count↗
PubMed2005

Golgi-mediated vacuolar sorting of the endoplasmic reticulum chaperone BiP may play an active role in quality control within the secretory pathway.

Quality control in the endoplasmic reticulum (ER) prevents the arrival of incorrectly or incompletely folded proteins at their final destinations and targets permanently misfolded proteins for degradation. Such proteins have a high affinity for the ER chaperone BiP and are finally degraded via retrograde translocation from the ER lumen back to the cytosol. This ER-associated protein degradation (ERAD) is currently thought to constitute the main disposal route, but there is growing evidence for a vacuolar role in quality control. We show that BiP is transported to the vacuole in a wortmannin-sensitive manner in tobacco (Nicotiana tabacum) and that it could play an active role in this second disposal route. ER export of BiP occurs via COPII-dependent transport to the Golgi apparatus, where it competes with other HDEL receptor ligands. When HDEL-mediated retrieval from the Golgi fails, BiP is transported to the lytic vacuole via multivesicular bodies, which represent the plant prevacuolar compartment. We also demonstrate that a subset of BiP-ligand complexes is destined to the vacuole and differs from those likely to be disposed of via the ERAD pathway. Vacuolar disposal could act in addition to ERAD to maximize the efficiency of quality control in the secretory pathway.

Androstadienes↗
PubMedDate not supplied

[Data analysis and quality control in radioimmunoanalysis. II. Evaluation of the internal and external quality in the quantification of pituitary gonadotropins].

The procedures for a systematic evaluation of the quality control of radioimmunoassay in general were described previously. In this report we present the parameters of quality control and their application to the radioimmunoassay (RIA) of pituitary gonadotrophic hormones, luteinizing hormone (LH) and follicle stimulating hormone (FSH) in serum. We present the results obtained in the intra-assay variation for the measurement of the pituitary gonadotrophic hormones in serum (LH and FSH) from 1983 to 1989. The results on bias and the inter-laboratory assessment through an external quality control scheme during the same period are also presented.

Bias↗
PubMed1982

The cost of quality control procedures in the clinical laboratory.

The impact of quality control procedures on the workload and the cost of the clinical laboratory during the last decade is explored. Quality control procedures are shown to represent a relatively constant share of test procedures for acute care admissions. The effect of automation on quality control testing in the laboratory has been to reduce the workload units per quality control test and thus to reduce the relative share of total laboratory costs incurred by quality control. The need to assess changes in the cost of quality control testing against any change in quality of laboratory output is emphasized.

British Columbia↗
PubMed2005

Mean and variance quality control for multiple correlated levels of replicated control samples.

Mean and variance rules for quality control are more powerful than rules based on individual values. An algorithm for applying such rules is described that controls type I errors (false alarms), while allowing for multiple levels of quality control samples, correlation between levels, small numbers of preliminary values, replication of samples and autocorrelation arising from random effects. Based on ANOVA and empirical approximations for small samples, the algorithm maintains a low per-batch probability of type I errors. Three statistics are computed, z(m), z(b) and z(w), which are shown by simulations to be primarily sensitive to a concordant shift in the quality control values, a discordant shift in the values, and an increase in random variability, respectively. Simulations also show that for a Gaussian distribution of analytical errors, the per-batch probability of a type I error is likely to be within the range 0.0045-0.0071 for two to four levels where there are 20-100 preliminary batches and the inter-level correlations are between zero and 0.8. This partial separation of out-of-control alarms into three components provides more assistance with trouble-shooting than do multivariate quality control schemes based on Hotelling's T2, while retaining comparable power.

Analysis of Variance↗
PubMed1995

The stability of survey-assigned assay values when surveyed control materials are used in a daily interlaboratory quality control program. The College of American Pathologists Chemistry Survey--Quality Assurance Service shared pool experience.

Two pools of lyophilized human control serum, distributed as challenges for the 1990 and 1991 College of American Pathologists Comprehensive Chemistry Surveys were employed consecutively as two-level, daily, quality control materials in College of American Pathologists Quality Assurance Service Regional Quality Control programs. Because the Chemistry Survey and Quality Assurance Service use identical method codes and the materials are essentially stable, the variation of differences among Chemistry Survey and Regional Quality Control assay values is a sensitive measure of both the variation of accuracy among calibrator-assigned values and of the matrix response among calibrator/reagent lots following the time of initial Chemistry Survey assay. In the two cycles of data comparison, the Regional Quality Control means for the assay values of 15 stable routine chemistry analytes showed no statistically significant differences from the initial Chemistry Survey for 295 of 361 analyte-method combinations studied 16 months later. Statistically significant changes between Chemistry Survey assay values and Regional Quality Control means most often occurred with closed rather than with open analytic systems and were predominantly in the same direction at both concentration levels. The magnitude of bias difference was usually less than the average within-laboratory standard deviation for the same analyte concentration. Of 64 analyte-pool combinations studied, a single instance of probable analyte instability was noted, ie, decreasing level I glucose during the first cycle. Our findings strongly support the usefulness of Chemistry Survey-assigned target values to help strengthen the intralaboratory accuracy base. They also point out the need for and the utility of Regional Quality Control-recalculated interlaboratory means to supplement assay values assigned at the time a control pool was put into use.

Chemistry, Clinical↗
PubMed1989

Allowable limit of error in clinical chemistry quality control.

Taking the National Clinical Chemistry Quality Control of China National Center for Clinical Laboratory as an example, I present this study of some problems with using the allowable error limit in present-day clinical chemistry quality control, and propose a new allowable error limit for use in external quality control in clinical chemistry.

Blood Chemical Analysis↗
PubMed1980

Applicability of various quality-control sera to assay of high-density lipoprotein cholesterol.

Effective internal quality control and external quality assessment of high-density lipoprotein cholesterol assay is made difficult by analyte instability, and the suitability of quality-control sera for this purpose has not been studied. We have therefore investigated the properties of 25 different control sera from 15 suppliers by estimating within-batch precision for the two precipitation procedures used most widely (phosphotungstate/Mg2+ and heparin/Mn2+ with enzymic measurement of cholesterol. Some sera had properties similar to those of fresh human serum, but others demonstrated poor precision for one or both procedures or contained apparent high-density lipoprotein cholesterol in unphysiological concentrations. A study of six sera indicated that between-batch precision was consistent with the within-batch findings. We found that eight of the 25 batches of quality-control serum we investigated may be used for internal quality control and external quality assessment of high-density lipoprotein cholesterol assay.

Chemical Precipitation↗
PubMed2000

[Intraoperative quality control in carotid surgery].

The intraoperative quality control in carotid surgery is performed by different methods: angiography, duplex-ultrasonography, transcranial Doppler ultrasonography, cw-Doppler, B-mode ultrasonography, pulsed Doppler with spectral analysis, angioscopy and flow-measurements. In Germany these measures are used only in one third of the carotid reconstructions. Especially with angiography and duplex-ultrasonography technical defects can be detected and differentiated if they were without clinical relevance like low-grade stenoses, small intima-flaps and residual plaques or needed to be reexplored. These are high-grade stenoses, acute thrombus-formations of the endarterectomised area and large intima-flaps. Abnormalities were detected in a mean of 17% of all carotid reconstructions by intraoperative control methods. In 5% severe irregularities lead to an immediate revision. Despite that there does not exist clear evidence whether the use of quality control methods reduces the perioperative neurological complication rate. It is not necessary to perform intraoperative quality control if meticulous operative technique with shunting and patch angioplasty is applied and a low perioperative complication rate is reached. For the documentation of the surgical result angiography can be recommended.

Angiography, Digital Subtraction↗
PubMed2000

[Quality control on antimicrobial susceptibility testings].

Performance of quality control in the clinical microbiological laboratory is markedly behind that of other laboratories. In particular, it remains indispensable even if the antimicrobial susceptibility test being carried out is standardized. In Japan, a standardized method of antimicrobial susceptibility testing has recently been established by the National Committee for Clinical Laboratory Standards and Japan Society of Chemotherapy. However, most laboratories do not perform quality control for antimicrobial susceptibility testing according to the standardized rules. The problem in quality control in laboratories causes things to remain as they are. As a review of laboratory quality control methods, we will show several cases of error that we encountered in our laboratory.

Japan↗
PubMed1995

[Quality control in anesthesiology].

The process of quality control and auditing of anesthesiology allows us to evaluate care given by a service and solve problems that are detected. Quality control is a basic element of care giving and is only secondarily an area of academic research; it is therefore a meaningless effort if the information does not serve to improve departmental procedures. Quality assurance procedures assume certain infrastructural requirements and an initial period of implementation and adjustment. The main objectives of quality control are the reduction of morbidity and mortality due to anesthesia, assurance of the availability and proper management of resources and, finally, the well-being and safety of the patient.

Anesthesia↗
PubMed1982

Nonmicrobial alternative to reagent quality control testing.

The traditional approach to quality control in microbiology involves the routine testing of both media and reagents with live microbial cultures. This is expensive, time consuming, and subject to the variables associated with the use of live organisms. A system of reagent quality control based on the pure chemical form of the metabolic end products important to the identification of the Enterobacteriaceae was evaluated. The metabolite reagent control system is simple, reliable, and extremely cost effective, and it eliminates the need for live microbial cultures and media for reagent quality control.

Bacteriological Techniques↗
PubMed1991

Mean and variance rules are more powerful or selective than quality control rules based on individual values.

Quality control rules based on individual values are compared with mean and variance rules using theoretical computations and simulations. Simple (1(3)s) and combined individual value rules, e. g. a 1(3)s/2(2)s/4(1)s/6 means rule, are all less powerful for detection of shifts of location than a mean rule, given identical type I errors. The mean rule is also more robust towards non-normality of data distributions. In most cases, the variance rule has more power towards increased scatter than individual value rules, and it always has the highest selectivity. Thus, the simple computations that are required for derivation of the mean and variance result in increased power or selectivity. In particular, in the computerization of quality control, the traditional mean and variance rules are preferable to more or less complicated "multi-rules" proposed for computerized quality control.

Analysis of Variance↗
PubMed1990

The use of retained patient specimens for haematology quality control.

Patient blood specimens constitute ideal quality control material in many respects. Although stability is a problem, patient specimens are sufficiently stable to allow their use in the control of short-term systematic error. The principal challenges involve the design of a system which combines excellent performance characteristics (probability of error detection and probability of false rejection) with a minimum of extra work. In the past, guidelines have been presented for an optimized quality control program using retained patient specimens in haematology. These guidelines call for the use of three retained specimens initially analysed only once, with subsequent analyses judged 'out of control' if they deviate from the initial result by a prescribed multiple of the long-term standard deviation. In practice, this system may result in a relatively high probability of false rejection of data (Pfr) due to inadequately established control ranges. Also, the maintenance of three retained patient specimens may be an excessive burden on small laboratories. We present data on the optimization of a quality control program using one retained specimen that is appropriate for use by smaller laboratories. The control rules and the number of initial analyses are adjusted to yield the highest possible probability of error detection (Ped while maintaining a low Pfr and a low additional workload. In addition, we present data concerning the control of satellite instruments by sharing patient specimens between the satellite instrument and a 'reference' instrument.

Computer Simulation↗