Basic Quality Control Research Articles

Multicenter study on in vitro characterization of dendritic cells

There is growing interest in the use of in vitro-expanded dendritic cells (DC) in cancer immunotherapy as cellular-based vaccines. However, the methods used for in vitro preparation vary widely between institutions. Therefore, a strong need exists for standardization, characterization and quality control (QC) of such vaccines. A first prospective multicenter pilot study was performed to investigate basic QC parameters of frozen/thawed DC. The study design was focused on comparison of test results for cell counts, immunophenotyping and cell viability. CD14+ monocytes were isolated from three healthy volunteers. The cells were expanded in vitro, matured and cryopreserved using a standardized protocol in one laboratory. The aliquots of cryopreserved DC and a panel of reagents were shipped to eight laboratories worldwide. The objective was to compare the results of non-functional QC assays between sites by testing identical DC vaccines and using a pre-defined test protocol. Measurements of nucleated cell (NC) content of thawed DC vaccines with different types of hematology analyzers (HA) gave similar results for the majority of sites. Immunophenotyping using identical clones of monoclonal antibodies for the detection of surface antigens (i.e. CD1a, CD14, CD16, CD83, CD86 and HLA-DR) provided mostly comparable results between laboratories with an acceptable level of variation. In contrast, highly different results between study sites were generated for measuring the viability of thawed DC by flow cytometry using 7-amino-actinomycin D (7-AAD) dye exclusion. In characterizing frozen/thawed DC vaccines, NC counts generated by HA yielded similar results between different laboratories. Furthermore, immunophenotyping of DC vaccines can be standardized between centers, i.e. by using identical reagents. Because of highly variable results between laboratories, 7-AAD viability testing of thawed DC needs to be studied further to identify potential causes for the observed variability.

Development of NEMA-based Software for Gamma Camera Quality Control

We have developed a cross-platform software application that implements all of the basic standardized nuclear medicine scintillation camera quality control analyses, thus serving as an independent complement to camera manufacturers' software. Our application allows direct comparison of data and statistics from different cameras through its ability to uniformly analyze a range of file types. The program has been tested using multiple gamma cameras, and its results agree with comparable analysis by the manufacturers' software.

Cloud motion vectors from MISR using sub-pixel enhancements

The operational retrieval of height-resolved cloud motion vectors by the Multiangle Imaging SpectroRadiometer on the Terra satellite has been significantly improved by using sub-pixel approaches to co-registration and disparity assessment, and by imposing stronger quality control based on the agreement between independent forward and aft triplet retrievals. Analysis of the fore-aft differences indicates that CMVs pass the basic operational quality control 67% of the time, with rms differences — in speed of 2.4 m/s, in direction of 17°, and in height assignment of 290 m. The use of enhanced quality control thresholds reduces these rms values to 1.5 m/s, 14° and 165 m, respectively, at the cost of reduced coverage to 45%. Use of the enhanced thresholds also eliminates a tendency for the rms differences to increase with height. Comparison of CMVs from an earlier operational version that had slightly weaker quality control, with 6-hour forecast winds from the Global Modeling and Assimilation Office yielded very low bias values and an rms vector difference that ranged from 5 m/s for low clouds to 10 m/s for high clouds.

Investigation of vitamin and mineral tablets and capsules on the Canadian market.

The goal of this study was to investigate the disintegrating properties of tablets and capsules containing minerals and vitamins commercially available on the Canadian market and to review their label information. The labels were examined for product-related information. The first disintegration test stage was performed using Simulated Intestinal Fluid (SIF) pH 6.8 for 20 minutes. Products which did not disintegrate were further investigated using USP disintegration conditions for dietary supplements. The provided label information is difficult to understand and in some cases pseudo-scientific. Thirty out of thirty-nine tablets and six out of ten capsules had a Drug Identification Number (DIN). Twenty-one of thirty-nine tablets and four out of the ten capsules did not disintegrate within 20 minutes. Using the USP disintegration conditions for dietary supplements nine tablet products did not fully disintegrate but all capsules passed the test. None of the three "time-released" products disintegrated under the applied conditions. Industry should follow already existing label recommendations more closely to allow the consumers to make an informed decision on their products by providing only essential information rather than using pseudo-scientific terms. The results of the disintegration study indicated that disintegration, one of the most basic quality control parameters, is still a concern for dietary supplements.

Within the Smorgasbord of Women’s Imaging, Do We Need to Improve Our Bone Appétit?

Bone Densitometry (DXA) has become an imaging tool used to screen and treat women for osteoporosis with a frequency approaching that of the screening mammogram. In fact, they are often exams that are ordered in tandem. As was once the case with mammography, we are now beginning to discover that we need to improve our technique and possibly insist on further education and certification for those who perform and interpret DXA exams. Should the industry strive to standardize scan acquisition and analyses software to make intermanufacterer comparisons not only possible but accurately comparable? A need for Quality Assurance Program standardization is evident in the lack of facilities performing basic Quality Control testing of the unit and technologist precision studies on a regular basis. As proven in a study in 2004, there is also room for improvement in the understanding, scanning, interpreting, and reporting of pediatric bone densitometry. It seems that a standardized Quality Assurance Program is needed by a central governing body perhaps ISCD (The International Society for Clinical Densitometry). ISCD is going to begin offering Facility Accreditation for those performing these skeletal assessments. It will assess every element involved in performing DXA exams, from the qualifications of personnel to quality control testing, scan acquisition, scan analyses, interpretation, and reporting. What will become optional in the Fall of 2006 may one day be mandated as was mammography if we don’t get our bones in order.

Europe to Cut Lab Animal Tests

European governments and industry plan to reduce animal testing and develop better alternatives. On 7 November, the European Commission (EC) and leading industry associations agreed to cut the number of animals used for basic research, toxicology, and quality control of health products from 11

National evaluation of the US Department of Housing and Urban Development Lead-Based Paint Hazard Control Grant Program: Study methods

The US Department of Housing and Urban Development (HUD) undertook an evaluation of its Lead Hazard Control Grant Program between 1994 and 1999. The Evaluation is the largest study ever done on the effectiveness of lead hazard controls implemented in residential dwellings. The Evaluation had several major objectives: determining the effectiveness of various lead hazard controls in reducing residential dust lead levels and children's blood lead levels, establishing the costs of doing lead hazard control work and factors that influence those costs, determining the rate of clearance testing failures and their causes, and identifying possible negative effects of lead hazard control work on children's blood lead levels. This paper reports the overall research design and data collection methods of the Evaluation. The large number of dwelling units enrolled in the Evaluation was possible only by the innovative partnership among HUD, the Evaluators, and the grantees. HUD and the Evaluators relied on the grantees for essentially all of the data collection. The 14 participating HUD Lead Hazard Control Grantees were responsible for implementing the lead hazard control programs in their communities and collecting the study data. This paper describes the methods for recruiting and enrolling dwellings and families, collecting environmental and housing data, interviewing participating families, and collecting data on lead hazard control work performed and its costs. The paper also describes the basic quality control and quality assurance procedures used. The principal outcome measures were lead in dust collected using wipes from floors, window sills, and window troughs and lead in blood collected from children who were 6 years old or younger at enrollment. Data collection was conducted before intervention, immediately postintervention, and 6 and 12 months postintervention. For a subset of dwellings undergoing an extended follow-up data were also collected at 24 and 36 months postintervention. This paper provides the context for subsequent reports that will describe such findings as the influence of lead hazard control work on serial dust lead levels, the influence of lead hazard control work on serial blood lead levels in children, the nature and costs of the lead hazard control work done at the dwellings, and the experience of the grantees in meeting clearance testing requirements.

Development of a laboratory model to test kinetic orthodontic friction

<h2>Abstract</h2> The classic in vitro studies of frictional resistance mostly utilize straight-line traction applied to the wire-bracket-ligation interface. Reports from these studies include relative quantification of either static or kinetic frictional resistance, but do not simulate the complexity of tooth movements observed with in vivo sliding mechanics. A prototype testing apparatus was designed, fabricated, assembled, and its performance evaluated. Results of the operating friction trials are reported as a function of integrated and quantified angular and linear bracket movements. The ability to integrate, in real time, linear and angular bracket displacement while maintaining precise positional control enables previously unattainable testing of the orthodontic archwire-bracket-ligation interface. In addition, flexibility to accommodate user-specificity is a highly desirable feature. It is concluded that the testing apparatus presented has the ability to allow for a high standard of basic hypothesis testing, product development, quality control, and product performance evaluation with relative ease.

Arrangement of Throughput Manipulator and Inventory Control in Plantwide Control

The arrangement of the throughput/inventory control in plantwide control is studied in this article. Based on the way the production rate change is handled, two basic product quality control principles are explored. For the case of the conventional control structure, i.e., constant reactor level and temperature, the importance of the interaction between the flow and composition dynamics is pointed out. A steady-state interaction measure, relative disturbance gain, is employed to evaluate the appropriateness of the material balance control. Moreover, the relative disturbance gain can be expressed in terms of the design parameters, e.g., composition and recycle ratio. This serves as a basis for the selection of the throughput manipulator. The results show that the external flow, i.e., feed or product flow, is preferred over the internal flows. For the cases of variable reactor holdup, the dynamic interaction becomes important. That means, despite having a perfect steady-state interaction measure, schemes with significant dynamic interaction lead to poor closed-loop flow dynamics. Thus, the material balance control should be designed such that the dynamic interaction is minimized. Therefore, the tuning of the flow dynamics becomes important. Results also show that we should use the external flow as the throughput manipulator and tune the inventory control loops such that the flow/composition interaction is minimized. Since flow/composition interaction is inherent in recycle processes, the results can be extended to more complex recycle processes, e.g., systems with more than one recycle streams, in a straightforward manner.

ANÁLISES DE PROTOCOLOS TELETERÁPICOS DE CONTROLE DE QUALIDADE DE ALGUNS SERVIÇOS LOCAIS, BASEADOS NO TG40 E ARCAL XXX

Considerando a importância da garantia da qualidade nos serviços de radioterapia, este trabalho tem como primeiro objetivo fazer uma avaliação dos testes propostos pelos protocolos oficiais internacionais TG40 e ARCAL XXX para os equipamentos de cobalto, acelerador linear e simulador. O segundo objetivo consistiu em se fazer uma avaliação dos testes que atualmente são realizados por alguns serviços de radioterapia nacionais e da América Latina, comparando-os com os apresentados nos protocolos citados. Dos resultados obtidos, observou-se que embora o TG40 apresente os testes básicos necessários para um controle de qualidade adequado, o ARCAL ainda sugere testes complementares. Dos resultados e discussões, concluiu-se que é necessário que os serviços de radioterapia implementem os testes de controle de qualidade básicos e indispensáveis aos seus equipamentos, e que os demais testes sejam implementados de acordo com as suas necessidades e disponibilidades. Como produto deste estudo, sugestões de protocolos são apresentadas para o trabalho de rotina, provenientes da fusão dos protocolos analisados.

The oncologic pathology report. Quality by design.

Objective To review tenets of basic quality assurance and identify opportunities for quality improvement in the laboratory assessment of prognostic factors. Design College of American Pathologists Q-Probes data obtained from hundreds of American laboratories throughout the 1990s are used to illustrate laboratory performance and practice opportunities in the preanalytic, analytic, and postanalytic phases of the total testing process. Results A wide range of performance deficiencies are documented, most in the preanalytic and postanalytic phases, and contributed by individuals outside and not under the control of the laboratory. In the analytic phase, the effectiveness of checklists on the content and completeness of reported diagnostic and prognostic data for breast and colon cancers is proven. Conclusions In the preanalytic phase, marked enhancements in quality would result from improvements in (1) patient and specimen identification, (2) adherence to patient-sampling and specimen-handling requirements, and (3) communication to the laboratory of the pertinent clinical context of the individual test. Once basic analytic quality control and laboratory quality assurance issues are resolved, a focus on standardization and enhancement of preanalytic and postanalytic communications and satisfaction of clinical expectations becomes the source of improved laboratory performance.

The oncologic pathology report. Quality by design.

To review tenets of basic quality assurance and identify opportunities for quality improvement in the laboratory assessment of prognostic factors. College of American Pathologists Q-Probes data obtained from hundreds of American laboratories throughout the 1990s are used to illustrate laboratory performance and practice opportunities in the preanalytic, analytic, and postanalytic phases of the total testing process. A wide range of performance deficiencies are documented, most in the preanalytic and postanalytic phases, and contributed by individuals outside and not under the control of the laboratory. In the analytic phase, the effectiveness of checklists on the content and completeness of reported diagnostic and prognostic data for breast and colon cancers is proven. In the preanalytic phase, marked enhancements in quality would result from improvements in (1) patient and specimen identification, (2) adherence to patient-sampling and specimen-handling requirements, and (3) communication to the laboratory of the pertinent clinical context of the individual test. Once basic analytic quality control and laboratory quality assurance issues are resolved, a focus on standardization and enhancement of preanalytic and postanalytic communications and satisfaction of clinical expectations becomes the source of improved laboratory performance.

The Principles of Clinical Cytogenetics

By Steven L. Gersen and Martha B. Keagle, 558 pp, with illus, Totowa, NJ, Humana Press, 1999.The Principles of Clinical Cytogenetics is a textbook and reference covering the gamut of cytogenetics; topics include basic molecular biology, cytogenetic nomenclature, quality control and quality assurance, prenatal cytogenetics, cancer cytogenetics, fluorescence in situ hybridization, imprinting, and genetic counseling, among others. Considering its large number of illustrations, this book is a relative bargain and should find wide applications. It will certainly fill a previously empty spot on the bookshelves of cytogenetic technologists and laboratory directors, genetic counselors, and clinical geneticists. Because of its clinical orientation, it should also be welcome in other clinical settings, such as in pathology residents' rooms. Teachers of some undergraduate and graduate courses in genetics and cytogenetics may find the book a good choice for their reading lists.Because this book is a compilation of works by different authors, the various chapters are not uniformly targeted to a particular audience. Some of the chapters cover very basic principles, while others resemble literature reviews. The chapter entitled “DNA, Chromosomes, and Cell Division” is a primer that covers elementary molecular biology and cell biology. In contrast, the chapter on cancer cytogenetics essentially assumes that the reader possesses an understanding of the concepts of oncogenes and tumor suppressor genes and their applications in cytogenetics. It does not contain a single molecular diagram of a gene fusion resulting from a recurring translocation. However, cancer cytogenetics is a massive subject suitable for an entire book on its own. Furthermore, this chapter focuses on the cytogenetic aspects of cancer and has a large number of useful tables and an impressive reference list. Some of the more circumscribed topics, such as structural rearrangements and spontaneous abortions, permit a more complete treatment and are well written. The chapter-to-chapter variation of this book has a very positive aspect in that there is something for everyone.Because chromosomes are inherently beautiful to those who work with them, a comment on the figures is in order. Most are good to excellent, but some could be improved. For example, the Q-banded karyotype on page 34 is speckled with white debris, the silver staining on page 84 will not be evident to those not already familiar with the process, and the fluorescence in situ hybridization signal over the marker chromosome on page 459 is not at all clear.There are a few inevitable mistakes. Perhaps predictably, some of the ones that may go unnoticed by novice cytogeneticists are in the nomenclature chapter. For example, the long form description on page 47 of an interstitial deletion is incorrect, and genes are not listed in pter to qter order in 2 fluorescence in situ hybridization examples on page 59. In the autosomal aneuploidy chapter, the definition of aneuploidy is at best confusing; it would have been better to stick with the usual definition of a chromosome number other than 23n.I point out these small problems in the hope that there will be future editions. This book was a substantial undertaking and provides a convenient resource for information not previously available in one place.

Development of BKD Hardware: Accomplishments and Opportunities

Automated Crystal Orientation Measurement/Mapping (ACOM) as used in the SEM by unattended interpretation of Backscatter Kikuchi Patterns from bulk surfaces (BKP)* has become an invaluable new technique for the quantitative characterization of microstructure on a grain-specific level. The principal objectives are to relate grain orientations and misorientations directly to grain location in the specimen surface, to determine the character of misorientations and grain/phase boundary planes, and to calculate derived entities such as microtexture and anisotropic local materials properties. These quantities are commonly depicted in pseudo-colors on the scanning grid to form Crystal Orientation Maps (COM) or similar “images” of the microstructure. Stereological as well as orientation related data, as most sensitive indicators of the production process and use of a material, are readily available for basic research and quality control. The three-dimensional representation of microstructure by consecutive sectioning is still a challenge to enable the study of inhomogeneity beneath the surface and the three-dimensional connectivity of multiphase material. Dynamic experiments are a further promising application of this new technique in the SEM.

Nanostructures of the dispersed organic metal polyaniline responsible for macroscopic effects in corrosion protection

Nano-particulate dispersions of the organic metal polyaniline in various paints at low concentrations cause tremendous effects in corrosion protection. Scanning Volta potential measurements and Electrochemical Impedance Spectroscopy are useful methods for basic research, product development and quality control of anti-corrosion coatings.

Identifying Bottled Water: A Problem-Solving Exercise in Chemical Identification

The availability of a variety of bottled waters from a number of sources provides a readily available resource for problem-solving exercises in chemical analysis. Students are challenged to identify water samples using the known chemical analyses of bottled waters. Several common water quality measurements such as hardness, alkalinity, and ion analysis can be used by students to identify the unknown water. This exercise develops problem-solving skills as students become familiar with basic lab techniques, quality control, data interpretation, and standard methods. Throughout the activity students become more conscious of both their data and data obtained from references. Students learn that data reported from a source are not absolute values, and develop varying degrees of confidence in data sources.

The use of quality management techniques and tools: an examination of some key issues

Research has been undertaken into the difficulties and key issues associated with the use of statistical process control (SPC), failure mode and effects analysis (FMEA), quality costing, quality function deployment (QFD), design of experiments (DOE) and the seven basic quality control tools. A 4-part classification - role in quality improvement, organisation and infrastructure, data collection and use and application - has been developed to examine the difficulties/issues associated with each of the techniques and tools. A number of issues have been identified which relate to all the techniques and tools examined, including management support, user understanding, integral approach, discipline and application. On the other hand, there are some issues, which relate to specific techniques and tools, including level of complexity, visual display, initial investment and overall status of TQM.

Achieving a balanced quality portfolio: The relative costs of quality control and enhancement schemes

This article points out that there are costs associated with schemes for ensuring quality in higher education, and the more elaborate the scheme the higher the cost. Further, the marginal quality returns decrease as the measures become more involved and more expensive. There are also differing relationships between cost and quality return for quality control and quality enhancement schemes. In the former, improvement in quality tends towards a plateau as teaching and courses reach some minimum acceptable standard. There may even be a decrease in quality if schemes become excessively time consuming or inquisitorial. Quality enhancement schemes show smaller reductions in marginal quality returns as investment increases. Workshop‐type schemes tend to peter out as the level of offering increases, but project‐type approaches continue to show returns unless the investment becomes very high. These relative cost structures are used as an argument for evaluating quality measures themselves, for simplifying quality control measures where necessary, and for a shift towards quality enhancement. It is suggested that institutions need a balanced portfolio of quality measures, with basic quality control schemes to ensure minimum standards, workshops up to the level of market demand, and remaining resources allocated for quality enhancement initiatives through schemes such as grants for educational development projects.

Compliance with the "recommendations SEPAR" on spirometry

The objective of this study was to assess Spanish performance of spirometry and to determine the extent to which practice is in accordance with the 1985 SEPAR recommendations. To that end we formulated a questionnaire with 31 items in two sections, 10 covering basic aspects of compliance with necessary techniques and 21 general questions. The questionnaire was sent to all SEPAR members. One hundred eight responses were received. The results show that the typical spirometric measurement was forced expiration without a bronchodilator test by way of a pneumotacograph, with simultaneous representation of the flow/volume curve. Calibration, when performed, is done daily with a 3 1 syringe and atmospheric data are checked. Spirometric measurements are usually obtained by a registered nurse, who also collects anthropometric data directly from the patient. The patient is usually seated with the nose occluded. At least three and at most eight satisfactory readings are obtained. The criteria for starting and ending the maneuver and the reference values used are those recommended by SEPAR. The equipment is washed weekly with soap and water; calibrations and equipment incidences are not recorded. The level of compliance with 1985 SEPAR norms for forced spirometry is adequate with respect to some technical equipment questions but deficient on basic procedure and quality control.

Quality control for SPECT systems.

A comprehensive set of acceptance tests is the basis for an effective quality control program. Acceptance tests indicate whether the scintillation camera meets published specifications but should also include evaluation of certain parameters not specified by the vendor but that can seriously affect image quality. Once a camera is "accepted," initial quality control tests serve as a benchmark for future measurements. Tomographic systems must be subjected to the same basic quality control program as planar cameras. Flood field images must be acquired and evaluated daily; spatial resolution must be tested once each week. Less frequently, parameters such as multiple-window spatial registration, collimator uniformity, system sensitivity, and camera "dead time" should be evaluated. Single photon emission computed tomographic systems require additional tests to ensure optimum performance. Center-of-rotation calibration and verification of detector registration are needed to avoid losses of spatial resolution. Flood corrections based on high-count images eliminate residual detector nonuniformiaties and correct for subtle collimator defects. Pixel size must be calibrated to avoid errors in attenuation correction and distortion when cardiac and brain reorientation software is used. Completed clinical studies must be checked for unacceptable patient movement and incomplete views. A quality control program may be time-consuming, but, from the standpoint of maximum benefit to patients and confidence in clinical interpretations, there is no alternative.