Effect of clofibrate (atromid S) on t 4 -by-column measurements.
Explore the source record for details and available documents.
Binding, Competitive↗
Biomedical subjects
E A Knesel
Publications and source records attributed to E A Knesel.
Cell preparation methods and criteria for sample adequacy. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.
ISSUES: Cell Preparation Methods Standardized fixation and optimal staining Sampling of cervix, sampling error, homogenization of sample, subsampling Assessment of liquid-based preparations: efficacy and economic impact Training and transitional procedures before full implementation of new technologies Criteria for Sample Adequacy Clinician responsibility for collecting and providing representative sample to laboratory Collection instruments, number of slides Cellular content of samples: evidence of transformation zone (TZ) sampling, number of squamous cells present, obscuring factors Screening issues CONSENSUS POSITION The conventional cervical smear remains the standard method of cervical cancer screening but has limitations in individual test sensitivity and specificity. Sample takers should: (1) receive appropriate training in sample collection, (2) be held responsible for providing the laboratory with appropriate samples, and (3) have their performance monitored. The instruments used for sampling should collect cells from both the ectocervix and endocervix; optimally, TZ sampling, represented by the presence of endocervical or squamous metaplastic cells, should be identifiable in samples other than atrophic specimens. The adequacy of a specimen (as judged microscopically) does not guarantee that it is representative of the cervix. Each cytology report should include a comment on cellular content/adequacy of the specimen. Liquid-based preparations may overcome many of the inherent problems with the conventional cervical smear. ONGOING ISSUES: We need further data on the cost-effectiveness of making two slides from cervical specimens and/or using two samplers rather than a single one. Do we have enough information to make recommendations as to the appropriate type of sampler to be used in particular situations, such as routine screening? What is the best method of screening for/detecting endocervical glandular neoplasia? How are such terms as unsatisfactory and inadequate defined in cervical cytology classifications other than the Bethesda System? What number and types of epithelial cells should be present (visualized) in a cervical smear or liquid-based preparation for it to be considered adequate? Do we need to have evidence of TZ sampling in specimens taken during the follow-up period after treatment of squamous intraepithelial lesion or after detection of endocervical glandular neoplasia? What criteria for obscuring factors, such as blood and inflammation, should be used in assessing adequacy? Cost-benefit analyses of utilizing liquid-based preparations are needed. Should we inform women about the technical details of the test methods available or chosen by the laboratory? Are women in a position to decide which method is the most appropriate to assess their cervical scrape sample? We need to obtain more information about the properties of proprietary liquid fixative/transport media with respect to inactivation of viral pathogens, tuberculosis and other bacterial pathogens and suitability for immunobiologic and molecular tests, etc. We need to obtain more information on the use of stoichiometric stains and the limitations of Papanicolaou stain for image analysis systems. The use of liquid-based preparations for nongynecologic cytopathology and ancillary tests must be considered, including criteria for adequacy. We need to obtain more information on the time required for and best methods of training experienced cytotechnologists to become competent at assessing liquid-based cervical preparations.
Cell Biology↗
Computerized training and proficiency testing. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.
ISSUES: Computerized technologies probably will revolutionize the field of gynecologic cytology in the next century. Such technologies will be useful in both training and evaluating proficiency. However, manual screening/review of gynecologic cytology preparations is the current "gold standard" for both training and assessment of proficiency. CONSENSUS POSITION: Training programs for cytotechnologists and pathologists should provide instruction and experience in new technologies, but their introduction may depend on the availability of equipment and staff. Advantages of digital images for training include standardization of teaching sets and interactive capabilities, allowing educational feedback. Computerized support/assistance devices aid in complete screening of the slide during training and provide feedback to cytologists on screening techniques. Liquid-based cytopreparatory instruments facilitate multiple glass slides for teaching or testing. Proficiency testing (PT) in cytology has similar quality assurance goals as in other areas of the laboratory, but the subjective nature of cytologic analysis poses many challenges for implementation. There is consensus that all cytology practitioners would like to know the proficiency of the laboratory. However, the majority question the value and validity of any large-scale formal testing programs. Locator and diagnostic skills are both critical in cytology, but assessment of each skill may occur in different ways using computerized technologies. Any type of assessment should provide educational feedback to participants. Psychometric issues in PT include the consideration of different types of validity, including face, content, construct and criterion related. The reliability or consistency of the testing event is also critical. A valid and reliable correlation between work performance and performance on a PT needs to be established. The goal is to ensure that PT will identify submarginal practitioners and that persons successful on PT are in fact competent. Any cytology PT program should also be considered in the context of other laboratory quality assurance tools and the entire cervical cancer screening program. Regulatory agencies should evaluate entire laboratory performance, while each laboratory director should assume primary responsibility for evaluating and documenting the competency and daily performance of each practicing cytologist. Professional scientific organizations should take the lead in recommending methods and standards of performance assessment. ONGOING ISSUES: A reliable method of correlating daily competency with results on PT is not yet established. Methods may evolve ever time using new technologies. The use of computerized techniques and images for assessment will require careful deliberation by experts as well as validation by practicing cytologists. Variables include diagnostic categories for testing, numbers of challenges per testing event, types of slide preparations and characteristics of the digital images. Availability of equipment and staff will affect the introduction of new technologies in different regions.
Cell Biology↗
Digital imagery/telecytology. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.
ISSUES: Optical digital imaging and its related technologies have applications in cytopathology that encompass training and education, image analysis, diagnosis, report documentation and archiving, and telecommunications. Telecytology involves the use of telecommunications to transmit cytology images for the purposes of diagnosis, consultation or education. This working paper provides a mainly informational overview of optical digital imaging and summarizes current technologic resources and applications and some of the ethical and legal implications of the use of these new technologies in cytopathology. CONSENSUS POSITION: Computer hardware standards for optical digital imagery will continue to be driven mainly by commercial interests and nonmedical imperatives, but professional organizations can play a valuable role in developing recommendations or standards for digital image sampling, documentation, archiving, authenticity safeguards and teleconsultation protocols; in addressing patient confidentiality and ethical, legal and informed consent issues; and in providing support for quality assurance and standardization of digital image-based testing. There is some evidence that high levels of accuracy for telepathology diagnosis can be achieved using existing dynamic systems, which may also be applicable to telecytology consultation. Static systems for both telepathology and telecytology, which have the advantage of considerably lower cost, appear to have lower levels of accuracy. Laboratories that maintain digital image databases should adopt practices and protocols that ensure patient confidentiality. Individuals participating in telecommunication of digital images for diagnosis should be properly qualified, meet licensing requirements and use procedures that protect patient confidentiality. Such individuals should be cognizant of the limitations of the technology and employ quality assurance practices that ensure the validity and accuracy of each consultation. Even in an informal teleconsultation setting one should define the extent of participation and be mindful of potential malpractice liability. ONGOING ISSUES: Digital imagery applications will continue to present new opportunities and challenges. Position papers such as this are directed toward assisting the profession to stay informed and in control of these applications in the laboratory. Telecytology is an area in particular need of studies of good quality to provide data on factors affecting accuracy. New technologic approaches to addressing the issue of selective sampling in static image consultation are needed. The use of artificial intelligence software as an adjunct to enhance the accuracy and reproducibility of cytologic diagnosis of digital images in routine and consultation settings deserves to be pursued. Other telecytology-related issues that require clarification and the adoption of workable guidelines include interstate licensure and protocols to define malpractice liability.
Computer Communication Networks↗
Roche Image Analysis Systems, Inc.
Explore the source record for details and available documents.
Clinical Trials as Topic↗
The false negative rate in cervical cytology. Comparison of monolayers to conventional smears.
OBJECTIVE: To compare cervical monolayers prepared by a density gradient technique to conventional smears. STUDY DESIGN: The study evaluated 2,863 patient samples. After conventional smears were prepared, the residual samples (collected in preservative fluid) were processed by the monolayer preparation system, which disaggregates the cells, removes nonclinical debris and layers the diagnostic material onto a microscopic slide. Slides were screened in Germany and the United States in masked studies. RESULTS: In the U.S. study, the false negative rate for the conventional smears was 9.4% when endocervical components were present and 16.7% when absent. The false negative rate for the monolayer preparation was 4.0% when endocervical components were present and 5.7% when absent. A comparison of the diagnostic results showed that the monolayer made possible the detection of 48 cases of low grade disease or higher that were not found on the conventional smear. The German study was independent but used the same samples. The results, although based upon the Papanicolaou classification, were similar. CONCLUSION: Cervical samples that are preserved in a liquid suspension and prepared using the density gradient monolayer technology have many advantages over conventional cervical cytologic smear preparations. The quality of cell preservation and presentation is superior. Elimination of obscuring material, homogeneity of the sample and standardized quality work together to produce preparations that can be effectively and reliably screened by cytotechnologists. These preparations should greatly enhance the reliability of machine-based screening in the future.
False Negative Reactions↗