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Assessing and enhancing the value of the UMLS Knowledge Sources.

The goal of the UMLS Project is to give practitioners and researchers easy access to machine-readable information from diverse sources. Assessment of the first experimental versions of the UMLS Knowledge Sources is essential to measuring progress toward that goal and to identifying needed enhancements. As of July 30, 1991, copies of the first edition of the UMLS Knowledge Sources had been distributed to 143 individuals and institutions; 66 had provided initial feedback information. The information received indicates that the UMLS Knowledge Sources will undergo broad testing in the patient care, medical education, library service, and product development environments. Preliminary data support the hypothesis that expanded coverage of routine clinical concepts is needed. Key enhancements planned for 1992 and beyond include expanded coverage of ICD-9-CM and CPT.

National Library of Medicine (U.S.)

Interactive query workstation: a demonstration of the practical use of UMLS knowledge sources.

The Interactive Query Workstation (IQW) has been developed to provide clinicians with a uniform program interface for retrieving medical-related information from various computer-based information resources. These resources can vary in content (bibliographic databases, drug information, general medical text databases), function (article retrieval, differential diagnosis, drug interaction detection, or drug dosage and administration information), and media formats (local hard disk, CD-ROM, local area network, or distant telecommunication link). IQW allows modular addition of new resources as well as extension of previously installed resources. The National Library of Medicine's three Unified Medical Language System (UMLS) Knowledge Sources, the Metathesaurus (Meta), the Semantic Network, and the Information Sources Map (ISM) have been incorporated into many aspects of IQW. Meta provides information about medical terminology and aids IQW in isolating the basic concepts from a clinician's question. The Semantic Network provides information about the categorization of concepts and possible relations between concepts. It also assists IQW in determining which queries are appropriate for a set of concepts contained in the clinician's question. The ISM provides information about the content available from a computer-based resources and aids IQW in selecting an appropriate resource from which to collect information. The computer-based resource selection is performed without user intervention. This interactive demonstration shows an environment which increases the accessibility of medical information to clinicians by utilizing the three UMLS Knowledge Sources.

Information Storage and Retrieval

CHARTLINE: providing bibliographic references relevant to patient charts using the UMLS Metathesaurus Knowledge Sources.

A successful medical informatics program helps its users to match their information needs as closely and efficiently as possible to the capabilities of the system. CHARTLINE is a computer program whose input is a free text, "natural language" patient chart in ASCII format. Using the UMLS Metathesaurus Knowledge Sources, CHARTLINE can suggest bibliographic references relevant to the patient case described in the chart. The program does not attempt to "understand" the natural language content of the chart. CHARTLINE only recognizes UMLS Metathesaurus Main Concept terms (or their synonyms) as they occur in the medical text, since those terms represent the tokens used to index the literature. The program depends on user feedback to determine which topics of a large number of potentially relevant subjects are of interest to the user.

Diagnosis, Computer-Assisted

Molecular model-building of amylin and alpha-calcitonin gene-related polypeptide hormones using a combination of knowledge sources.

Amylin is the major component of the amyloid found in the pancreases of noninsulin-dependent diabetics (type 2 diabetes). It is a 37 amino acid polypeptide and has been shown to have 46% sequence identity with the neuropeptide alpha-calcitonin gene-related peptide (alpha-CGRP). Both amylin and alpha-CGRP are known to be potent inhibitors of glycogen synthesis in stripped rat soleus muscle. Secondary structure prediction and tertiary structure model-building show the two polypeptides to have an alpha-helix/beta-strand motif similar to that observed in the insulin B-chain. The results have been supported by CD spectroscopy, although there is no sequence similarity between insulin and amylin/alpha-CGRP. Aggregation states have been predicted based on the dimeric and hexameric arrangements seen in porcine insulin. Rat and hamster amylin have a changed sequence motif in the beta-strand which results in lack of amyloid formation and type 2 diabetes. This, we propose, is caused by disruption of hydrogen bonding which prevents the formation of the dimer.

Algorithms

Oral health knowledge and sources of information among elementary schoolchildren.

The dental health knowledge and sources of health information of 848 elementary schoolchildren (aged 9-12) in southwestern Michigan were assessed. Demographic parameters (education level, percent below poverty level, median income level) of the area were similar to state and national averages. The children were found to have some knowledge of caries and periodontal disease prevention, yet basic misconceptions were evident. More than one-third of the children thought that plaque should only be removed by a dentist. While 75 percent of the subjects knew that fluoride protected teeth from decay, only 4 percent of the children identified fluoridated water as the best source of this preventive agent. Knowledge of pit and fissure sealants was limited. Extent of correct dental knowledge was not related to age, sex, or mean DMFS scores. Children who answered the most questions correctly named parents and family as their source of information; dentist's office was the second most frequently mentioned source. Findings suggest a need to correct basic misinformation about dental health and to inform children about current efficacious preventive agents.

Child

Early understanding of perception as a source of knowledge.

Two studies investigated preschool children's ability to infer another person's knowledge or ignorance on the basis of that person's recent perceptual experience. In Experiment 1 children were questioned about their own and a puppet's knowledge of a hidden object's color and about their own and the puppet's ability to see the hidden object. Three- and 4-year-olds attributed knowledge and perceptual experience to the person (either themselves or the puppet) who had viewed the hidden object, but not to the person who did not view it. Experiment 2 further investigated 3-year-olds understanding of perception as a source of knowledge. Children were asked to indicate which of two puppets, one who had viewed a hidden object and one who had not, would be able to tell them the object's color. Children chose the correct puppet more often than would be predicted by chance. The results of these experiments suggest that understanding of perception as a source of knowledge is present by the age of 3 years.

Attention

Evaluating the impact of a promotional campaign for screening mammography: women's knowledge and sources of awareness.

The Breast X-Ray Programme of the Central Sydney Health Service was advertised by generalised strategies aimed at the total community, including poster and pamphlet distribution, and strategies aimed at general practitioners, supplemented by written invitations and recommendation from the general practitioner, invitations for friends, and invitations from the service using the electoral listing. In order to evaluate the reach or impact of the promotional campaign in the Drummoyne local government area, telephone interviews were conducted with women aged 45 to 70 randomly selected from the community. Women's knowledge about breast cancer, screening and the Breast X-Ray Programme, plus sociodemographic characteristics, were obtained before screening (n = 628), 10 months (n = 93) and 2 years after screening started (n = 206). While knowledge about risk did not change, significant increases were found in the proportion of women who had heard of mammography, screening mammography specifically and the screening van. In addition there were significant increases in the proportion of women exposed to information about screening mammograms. The campaign generally had an equal effect on different sociodemographic but managed to achieve greater effects in women of non-English-speaking backgrounds and lower occupational status. A random sample of program attenders aged 45 to 70 (n = 763) were asked how they found out about the van. 'Seeing the van' was the most consistently reported source of awareness. Others included 'GPs' 'newspapers', 'other print media' and 'personal networks'. Women with additional qualifications since leaving school were more likely to state 'newspaper' and 'other print media' as a source.

Aged

Data-source effects on the sensitivities and specificities of clinical features in the diagnosis of rheumatoid arthritis: the relevance of multiple sources of knowledge for a decision-support system.

An experimental computer system was developed to support diagnosis of rheumatic disorders by computing diagnostic probabilities using modified likelihood ratios. The authors examined whether the performance of the model was affected by the settings in which the data used to derive the likelihood ratios were collected. The sensitivities and specificities of various clinical features for diagnosing rheumatoid arthritis (RA) were obtained from: 1) a study of 1,570 consecutive outpatients at a rheumatology clinic; 2) a review of the literature; 3) estimates by rheumatologists; and 4) a population study. Considerable variations in sensitivity and specificity but satisfactory agreement in likelihood ratios were found across the four data sets. The likelihood ratios were then used to compute the probabilities of RA in a test series of 570 of the rheumatology clinic outpatients. The model's diagnoses with likelihood ratios from the other sources were adequate. When the likelihood ratios from these sources were combined, discrimination came close to what could be achieved by using the likelihood ratios based on the data from the clinic. The method applied in the study, which makes use of variation of input data instead of variation of test series, and the results are relevant to assessing the external validity and transferability of Bayesian decision-support systems.

Adolescent

[Prions and Trypanosoma as a source of knowledge of the brain].

Recent research on prions and trypanosomes is reviewed as they constitute examples of how infectious agents can cause degenerative diseases or functional disturbances in the nervous system. Prions are novel, transmissible pathogens causing degenerative diseases of the central nervous system both in humans and in animals. Kuru, Creutzfeldt-Jakob's disease and Gerstmann-Sträussler-Scheinker's (GSS) syndrome illustrate the acquired, sporadic and genetic manifestations of the human prion diseases, respectively. Prions are composed largely, if not entirely, of an abnormal isoform of the prion protein, which is a normal cellular protein occurring at high concentrations in the central nervous system. Specific mutations in the prion gene may cause the sporadic and hereditary human disease. S B Prusiner's group at the University of California has used genetic engineering techniques to recreate GSS syndrome by transplanting the mutated prion gene into mice in which the effects of the prion protein genes can then be studied. Trypanosomes are extracellular parasites which cause distinct functional disturbances of the nervous system, although they do not penetrate the blood-brain barrier. Factors are now being isolated in the interactions between the parasites and the immunesystem, and the effects of such factors on the functional properties of neurons are studied.

Animals

A blackboard architecture for automating cephalometric analysis.

This paper describes a principled attempt to use artificial intelligence methodologies for interpretation of lateral skull X-ray images. Lateral skull X-ray images are routinely used in cephalometric analysis to provide quantitative measurements useful to clinical orthodontists. Manual and interactive methods of analysis are known to be error-prone, and time-consuming. Previous attempts have been made to automate this analysis, using conventional algorithmic approaches. Unfortunately such systems typically fail to capture the expertise and adaptability required to cope with the variability in biological structure and X-ray image quality found in cephalograms. The present system makes use of a blackboard architecture and multiple knowledge sources within an integrated model-based system. A data-gathering system allows models of feature appearance and location to be built from examples. Blackboard and task control modules allow specific knowledge-based modules to act on information available to the blackboard. Knowledge-based modules include location hypothesis, intelligent segmentation, and constraint propagation systems. Results from a working experimental system are given, and compare favourably with previous algorithmic solutions.

Artificial Intelligence