Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “quality control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,315 records · Page 73Linked to original sources
PubMed1983

Thallium-201 imaging artifacts not detected by technetium-99m or cobalt-57 quality-control testing.

Early stages of hydration in a sodium iodide crystal may cause artifactual "hot" spots on thallium-201 heart images. This phenomenon was observed when a mobile gamma camera was used even though the daily quality-control flood-field views revealed no apparent abnormalities. Nevertheless, hot spots were visible on thallium-201 and xenon-133 flood-field images. With asymmetric photopeak positioning using a technetium-99m source, hot spots were noted in addition to phototube nonuniformities. Subsequently, the camera head was disassembled, the crystal was inspected visually, and the crystal seal was found to be broken. Hydration of the crystal was confirmed by the camera manufacturer. Quality-control procedures should test for hydration-induced artifacts on a regular basis.

Animals↗
PubMed2001

[Quality Control in Umbilical Cord Blood Bank]

Recent clinical reports have demonstrated that the use of umbilical cord blood (UCB) opened a new source of stem cell for hematopoietic stem cell transplantation, leading to the development of cord blood banks world-wide. Prior to the large scale construction of UCB banks, quality control must be performed for health care providers and manufactures. With increasingly stringent regulatory requirement in blood industry, quality control is playing an important role in the operation of blood centers and stem cell laboratories. Reviewed the lectures in the biology of UCB and UCB banks published in recent years, our experiences were discussed in setting up Shandong blood bank to define process variables associated with the collection of UCB, to determine and optimize the procedures and materials used, to ascertain how UCB can be processed in clean room as mononucleated cell preparations, and to analyze using of long-term storage of UCB in research and clinic in the future. Our conclusions are: (1) the establishment of UCB banks for use in transplantation appears to be easy, effective and particularly suitable approach in China under cGMP conditions; (2) the procedures for volume reduction by closed and semi-automated blood processing system, SSP HLA typing, biocode and local computer net, microbiological tests and the 50 ml cryobags for storage constitute a cost efficient system for large-scale UCB banking; (3) the average of 60 ml UCB collection may contain sufficent marrow repopulating cells for children and most of adult recipients; and (4) hematopoietic stem and progenitor cells in cord blood have a more potent proliferative ability than those derived from bone marrow in cell expansion potentials.

Journal Article↗
PubMed2004

The cartilage-sparing versus the cartilage-cutting technique: a retrospective quality control comparison of the Francesconi and Converse otoplasties.

From a total of 281 patients with protruding ears who underwent a bilateral otoplasty between 1990 and 2001, a group of 28 (10%) was selected for a retrospective quality control study. The goal was to compare two methods of otoplasty, the Francesconi, a cartilage-sparing technique, and the Converse, a cartilage-cutting technique, in terms of objectively measurable and subjectively discernable differences in results. Objective parameters included measurement of the three cephaloauricular distances and the conchoscapal angle. An independent plastic surgeon performed the evaluation by means of a systematic evaluation system for rating cosmetic surgical procedures and a 5-point visual analog scale for rating satisfaction. The patients' subjective rate of satisfaction also was investigated using the 5-point scale. The mean medial and inferior cephaloauricular distances were significantly smaller in the Francesconi group. The concoscaphal angle was 90 degrees, or less in all the patients of the Francesconi group, but more than 90 degrees in eight patients (57%) of the Converse group (p = 0.041). Accordingly, the independent surgeon found adequate correction of protrusion in 86% of the Francesconi group and 50% of the Converse group (p = 0.050). His satisfaction rate was significantly in favor of the Francesconi technique (p = 0.006). Not unexpectedly, the patients' satisfaction rate was comparably high in both groups, and there was no statistical difference between them. In conclusion, the quality control led to a clear preference of the Francesconi over the Converse otoplasty. In addition, the assessment of the postoperative results with the systematic evaluation system offered an excellent information base by which to judge the results of otoplasty. Consequent use of this evaluation system will lead to progress in the surgical procedure.

Adolescent↗
PubMed1983

Assessing a quality control program for erythrocyte preservation and attempts to improve quality of cells after storage at +4 degree C.

About 22 in vitro parameter values were used to evaluate the condition of erythrocytes stored at +4 degrees C in SAGM (1) medium for 28 and 42 d. The parameters were related to such different functions of the erythrocyte, as glycolysis, ion transport, purine metabolism, membrane function and membrane morphology immediately after storage and after subsequent incubation at physiological conditions for 30 min. The evaluation included comparison with posttransfusion viability after 42 d of storage. The investigation gives information in statistical terms about relations between the parameter values and their change with storage time. Total adenylates are superior to ATP in predicting post transfusion viability. There is a good correlation between the in vitro parameters: total adenylates, morphology score and erythrocyte fluidity.

Adenine Nucleotides↗
PubMed2000

How the media do drugs: quality control and the reporting of drug issues in the UK print media.

Exaggeration, distortion, inaccuracy, sensationalism; each of these labels has been consistently applied to the reporting of drug related issues in the print and other media over the last 40 years and beyond. This research sought to understand what quality control mechanisms are employed by the UK print media in relation to issues related to illicit drugs to ensure accurate, informed and appropriate reporting. It was found that the print media in the UK employ almost no quality control mechanisms to ensure that such reporting takes place and that they predominately rely on the demonstrably insufficient qualities of the 'good reporting' skills that journalists bring to their research and writing. What concerns did exist regarding accuracy related predominately to protecting the publication from being sued for libel and no specific journalistic expertise of drug issues was considered necessary. A discussion of these issues is undertaken followed by the recommendation for the production of a negotiated media guide.

Journal Article↗
PubMed1985

[Quality control in obstetrical ultrasound diagnosis].

Experience with sonographic pregnancy care have demonstrated the necessity of quality control. Before a person is licensed to take account for sonography he should prove, that he has performed a certain number of examinations and that he is holding a file of documents on these examinations. This certificate should ensure that the fundamental knowledge of foetal sonographic anatomy and biometry as well as of possible signs of foetal malformations have been correctly acquired. As a provisional arrangement until sonography is fully integrated into gynaecological education, an examination by a board would appear to be desirable.

Cephalometry↗
PubMed2006

An efficient HPLC method for the quantification of isoflavones in soy extracts and soy dietary supplements in routine quality control.

Food supplements containing soy extracts are increasingly used to treat menopausal complaints. For the quality control of such products a RP-HPLC method for the quantification of daidzein, genistein, glycitein and their respective glucosides and acetylglucosides in soy extracts and nutraceuticals was developed and validated. The extraction of the samples is very simple and avoids time-consuming handling and expensive cartridges or reagents. The compounds are quantified by internal standardization with 4'-hydroxyflavanon which is easily available at a reasonable price. On a base-deactivated C18 column good separation and excellent peak shape of the analytes are achieved in short time by gradient elution with water and acetonitrile. Accompanying substances do not interfere. The method was applied to the analysis of different commercial soy preparations.

Calibration↗
PubMed1997

Quality control for DNA contamination in laboratories using PCR-based class II HLA typing methods.

Quality control (QC) in laboratories performing molecular histocompatibility class II typing often includes a polymerase chain reaction (PCR) approach for monitoring DNA contamination. An oligonucleotide primer set was designed, (RBQBf/RBQBr), which is specific for nonpolymorphic regions of the DR-B, DQ-B, and DP-B consensus sequences with an expected PCR product size of 81 bp. RBQBf/RBQBr detected genomic DNA from reference cell lines LWAGS and BM21 (50 to 100 picograms) as well as DR-B, DP-B, and DQ-B amplicon (1 copy). Additionally, RBQBf/RBQBr detected SSP products from routine DR-B and DQ-B typings. Validation studies employing controlled DNA contamination of laboratory surfaces revealed that increasing amounts of wipe test samples (5% to 20% v/v) were inhibitory to the wipe test PCR, whereas lower amounts (1% to 2%), or alternatively, a diluted wipe test sample, increased the sensitivity of the test and optimized the results. Collectively, this study describes a primer set, RBQBf/RBQBr, which detects both genomic DNA and DR-B, DQ-B, or DP-B amplicon and furthermore illustrates the necessity of routine testing for potential inhibitory factors that may be introduced into the wipe test PCR.

Base Sequence↗
PubMed1989

[Microbiological quality control of lipsticks which are on the market in our country].

In this study, microbiological quality control of lipsticks has been investigated. In 81 samples, we found that 34 of them (42%) had total aerobic plate count and 19 of them (23.5%) were found to consist mold and yeast which are not allowed by the cosmetic regulations. In none of the samples, pathogen microorganisms such as S. aureus, P. aeruginosa, E.coli, Salmonella and Shigella were detected. Indeed, after carefully examining of the microbiological content of these lipsticks, their biostatistical efficiency was also determined. In each counting procedure, for different bacteria, it was found that only one sample was effective at the 3rd and 14th day. The remaining 9 lipstick samples (90%) were kept under investigation until the end of the testing procedure on the 28th day.

Bacteria↗
PubMed1993

Genetic algorithms-based design and optimization of statistical quality-control procedures.

In general, one cannot use algebraic or enumerative methods to optimize a quality-control (QC) procedure for detecting the total allowable analytical error with a stated probability with the minimum probability for false rejection. Genetic algorithms (GAs) offer an alternative, as they do not require knowledge of the objective function to be optimized and can search through large parameter spaces quickly. To explore the application of GAs in statistical QC, I developed two interactive computer programs based on the deterministic crowding genetic algorithm. Given an analytical process, the program "Optimize" optimizes a user-defined QC procedure, whereas the program "Design" designs a novel optimized QC procedure. The programs search through the parameter space and find the optimal or near-optimal solution. The possible solutions of the optimization problem are evaluated with computer simulation.

Algorithms↗
PubMed1982

Vial-to-vial variation of a stabilized liquid quality control serum.

The vial-to-vial variation of a new ethylene glycol stabilized liquid quality control serum (DecisionTM, Beckman Instruments, Inc.) was evaluated. Intervial variation was compared with intravial variation by analyzing multiple vials in duplicate for 22 different analytes at three different concentration levels. The data were examined the Anova statistics partitioning the total variance into the variance within bottle, and the variance between bottle. The F-statistic at P = 0.05 was used to assess the significance of the results. It was concluded that there is bottle to bottle homogeneity for the analytes studied. Other advantages of this liquid material are potential decreased wastage of material due to aliquoting only the required amount of serum, and increased savings in labor time due to elimination of reconstitution that is needed for lyophilized material.

Blood↗
PubMed2001

School meals in Catalonia: surveillance and quality control.

The Education Council of the Catalonian government drew up a programme to improve the quality control of school canteens in Catalonia. The objectives of this programme were to contribute to developing healthier eating habits in school children through school canteens and to improve school canteen services considering other aspects such as service, operation, management, end-users, frontline staff and supervisors of menu planning. This paper deals with two programme components aiming at introducing Nutrition in the school syllabus and school menu assessment. Various departments, organisations and associations were involved in programme development and implementation. Initial analysis was based on information collected from formal administrative reports completed by a survey on 100 primary schools. From this preliminary analysis it was concluded that problem identification needs to be completed by an understanding of underlying reasons in order to design adequate solutions and guarantee implementation.

Adolescent↗
PubMed1988

Quality control of rheumatoid factor (RF) testing in Finland.

RF has been on the national laboratory quality control program since 1981. A pilot study had showed that most participants would be small laboratories performing qualitative slide latex tests only. Since we nevertheless wanted to be able to extrapolate test sensitivity data for each laboratory, we have sent out sets of 5-6 coded samples that in fact constitute a double dilution titration series. RF positive sera were pooled and the material calibrated with the WHO RF standard. The samples have contained 5-160 IU RF/ml and have been distributed once a year. The number of participants has varied from 58 to 104. Interlaboratory variation has diminished considerably since 1981. Inversions in the estimates of RF contents in the sample series have been notably rare. Waaler-Rose returns have mostly been too small to permit statistical evaluation. The same so far goes for the turbido- and nephelometric methods, in use since 1985.

Humans↗
PubMed1993

Quality control study of the Italian group of cytometry on flow cytometry cellular DNA content measurements.

A quality control study on DNA flow cytometry, extended to 43 national laboratories, has been carried out by the Italian Group of Cytometry, using defined fixed suspensions of cultured human leukemia K562 cells and human blood lymphocytes. The participating laboratories were allowed to follow their own staining and measurement protocols. Aliquots of cellular suspension had to be measured three times on the same day and two other times on different days. A large heterogeneity of procedures emerged among participants. The average of mean DNA index laboratory values, from 36 laboratories who sent evaluable data, was 1.68, with a range from 1.49 to 1.97. The coefficients of variation ranged from 2.35 to 9.39% and from 2.79 to 8.5% for diploid and aneuploid peaks, respectively. Statistical analysis of the results showed quite good intralaboratory reproducibility, but statistically significant differences were observed among laboratories, for both DNA indices and coefficients of variation. These differences appear to be consistent. For standardization, it is essential that efforts should be made to identify the main sources of variation and to control them.

Analysis of Variance↗
PubMed1988

A rapid sperm motility bioassay procedure for quality-control testing of water and culture media.

A rapid bioassay procedure is described for quality-control testing water and apparatus used in the preparation of media for gamete and embryo culture. This bioassay is based on the sensitivity of hamster epididymal spermatozoa to contaminants present in water and/or in the culture apparatus. The bioassay is usually performed using a modified Tyrode's solution as the sperm culture medium, although complex media can be used. The sensitivity of this test is greatly enhanced by the absence of protein in the medium. The bioassay has been used to detect impurities in water prepared by a standard cartridge filtration system and to verify that reverse-osmosis pretreatment of water could eliminate the problem. It has also detected toxic contaminants leached from syringe filters during medium sterilization. The bioassay is simple to perform and can be completed in 1 working day. It may be a useful alternative to the conventional mouse embryo tests that are in widespread use in human in vitro fertilization (IVF) laboratories.

Animals↗
PubMed1993

[Comparative evaluation of unfractionated and low molecular weight heparins. Results of the French Etalonorme interlaboratory quality control].

Four recent interlaboratory surveys have been conducted by the French National "Etalonorme" Group of Quality Control in Haematology, involving about 3,800 laboratories working in coagulation. They have been concerned with human lyophilised plasma samples heparinized in vitro either with unfractionated heparins (UFH), or with low molecular weight heparins (LMWH) (Fragmin 89 D, and Fraxiparin 90 A). The doses added simulated therapeutic situations or were on the border-line of over- or underdosage: UFHs 89 B3/B4, 0.14 and 0.22 IU/ml; 89 C3/C4, 0.3 and 0.4 IU/ml respectively; LMWHs: D3-A3, 0.6; and D4-A4, 1.2 IU/ml. Automated partial thromboplastin times (APTT) were prolonged at these high doses of LMWH, due to noticeable residual anti-IIa activity. A relationship between APTT and heparinaemia was observed with both types of heparin; sensitivities of cephalin reagents to heparin were also noted, but they were different for UFH compared to LMWH. Dispersion on APTT results was still high (CV: 12-23% for the UFH samples, 12-19% for the four LMWH samples). Dispersion on heparin determinations was higher for UFH than for LMWH, even for lower anti-IIa activity, but they involved more heterogeneous assays. The anti-Xa activity for LMWH samples was mainly determined using clotting assays (70% of the laboratories) with larger dispersions (CV: 32-37%), than those observed on amidolytic assays (CV: 28%); however, these amidolytic assays were performed in 90% of the laboratories with only two reagents available from a single manufacturer. The clotting techniques, more than the colorimetric assays, seemed to underestimate the high heparinaemias.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Assay↗