Biomedical subjects

W T Hole

Publications and source records attributed to W T Hole.

12 recordsLinked to original sources

PubMed2000

Discovering missed synonymy in a large concept-oriented Metathesaurus.

The Unified Medical Language System (UMLS) [1, 2] Metathesuarus is concept-oriented; its goal is to unite all names with identical meaning in a single Concept. The names come from its constituent vocabularies or "sources"--a wide variety of biomedical terminologies including many controlled vocabularies and classifications used in patient records, administrative health data, bibliographic, research, full-text, and expert systems. Many offer little definitional information, and many are not themselves concept-oriented, so identifying synonymy is a challenging semantic task [3]. The rapidly increasing size of the Metathesaurus makes the task daunting, demanding effective computational support; there are more than 1.5 million names for 730,000 concepts in the January 2000 release. Vocabularies are added and updated using sophisticated lexical matching, selective algorithms, and expert review [4, 5, 6]. Yet the result is imperfect; we have discovered and corrected missed synonymy in approximately 1% of previously released concepts each year. This paper reviews general methods for finding missed synonymy and describes several specific novel approaches which we have found effective.

Algorithms↗

PubMed1998

Beyond synonymy: exploiting the UMLS semantics in mapping vocabularies.

The Unified Medical Language System (UMLS) contains semantic information about terms from various sources, each concept can be understood and located by its relationships to other concepts: this is a result of the organizing principle of semantic locality. We describe a method in which the semantic relationships between concepts are used to map concepts from different vocabularies in the UMLS. Applied to mapping concepts to MeSH, this method is able to map 50 to 65% of the non-MeSH concepts to MeSH. A manual review of the mapping shows a relevance rate of 61%. Causes of failure include a lack of consistently represented relationships in the UMLS, and some inconsistencies in the categorization of the concepts. The limits of this method are discussed, as well as possible adaptations for other uses.

Algorithms↗

PubMed1996

MEME-II supports the cooperative management of terminology.

Health care enterprises need enterprise-wide terminologies to compare, reuse and repurpose health care descriptions. But once they are created, these terminologies need to be maintained and enhanced to sustain their utility and that of the descriptions encoded with them. MEME II (Metathesaurus Enhancement and Maintenance Environment, Version II) supports the required activities and enables enterprises to leverage their investment in terminology and descriptions by permitting remote-extra-enterprise-enhancements to terminology to be incorporated locally, and local-intra-enterprise-enhancements to be shared remotely. MEME II represents all changes to terminologies as data, or "actions," that can be interpreted by an "action engine." These actions, or messages, represent semantic "units of work" that can be interpreted by other copies of MEME II. The exchange of update messages increases the likelihood that the comparability of terminology-based health care descriptions can be sustained.

Information Systems↗

PubMed1995

Merging terminologies.

A terminology is a systematic, authoritative collection of concept names, or terms, in some domain. No single terminology names all the important concepts in biomedicine. One approach to creating a more comprehensive biomedical terminology is to merge existing biomedical terminologies, as the UMLS( Metathesaurus( has done for the last six years. Because existing terminologies may overlap--for example, one terminology may name a concept also named by another terminologyQthe terminologies in the Metathesaurus must be merged. Some terminologies suggest merges through their structure or content e.g., they suggest synonyms or connections to other terminologies; other merges can be suggested by algorithm. Regardless, all merges in the Metathesaurus must be approved by a human editor with appropriate domain knowledge. By the time Meta-U96 is released early in 1996, one prototype and seven released versions of the Metathesaurus will have been produced by a sequence of four qualitatively different methods, named for the way in which they merge terms: #1 "Term Rewrite Rules, #2 "Transitive Closure on Facts," #3 "Fact-at-a-Time Concept Merging," and #4 "Action-at-a-Time Object Processing." The development of each method has been constrained by the annual Metathesaurus release schedule. The first two methods made the best use of limited computational resources, and the last two make better use of human editing resources.

National Library of Medicine (U.S.)↗

PubMed1993

The ranking algorithm of the Coach browser for the UMLS metathesaurus.

This paper presents the novel ranking algorithm of the Coach Metathesaurus browser which is a major module of the Coach expert search refinement program. An example shows how the ranking algorithm can assist in creating a list of candidate terms useful in augmenting a suboptimal Grateful Med search of MEDLINE.

Algorithms↗

PubMed1993

The UMLS Metathesaurus: representing different views of biomedical concepts.

The UMLS Metathesaurus is a compilation of names, relationships, and associated information from a variety of biomedical naming systems representing different views of biomedical practice or research. The Metathesaurus is organized by meaning, and the fundamental unit in the Metathesaurus is the concept. Differing names for a biomedical meaning are linked in a single Metathesaurus concept. Extensive additional information describing semantic characteristics, occurrence in machine-readable information sources, and how concepts co-occur in these sources is also provided, enabling a greater comprehension of the concept in its various contexts. The Metathesaurus is not a standardized vocabulary; it is a tool for maximizing the usefulness of existing vocabularies. It serves as a knowledge source for developers of biomedical information applications and as a powerful resource for biomedical information specialists.

MEDLINE↗

PubMed1991

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.)↗

PubMed1990

A case report of naltrexone treatment of self-injury and social withdrawal in autism.

The endogenous opiate release theory of self-injurious behavior (SIB) was investigated through double-blind placebo-controlled administration of naltrexone hydrochloride (Trexan) to a 14-year-old autistic and mentally retarded male for treatment of severe SIB. Results yielded a marked decrease in SIB during two phases of active drug treatment, though SIB did not revert to originally observed placebo levels during a second placebo phase. An increase in social relatedness also was observed during phases of active drug treatment. Opiate theories of self-injury and the possible interrelationship of self-injury with pituitary-adrenal arousal and with social relatedness are discussed.

Adolescent↗

PubMed1989

Effects of naloxone and naltrexone on self-injury: a double-blind, placebo-controlled analysis.

The effects of naloxone hydrochloride (Narcan) and naltrexone hydrochloride (Trexan) on the pervasive self-injury of a 12-year-old autistic and mentally retarded girl were examined. Using separate multiple schedule (A1/B/B') and withdrawal (A-B-A1B-A1) single-subject experimental designs, we investigated the effects of both opiate antagonists in serial fashion under double-blind, placebo-controlled conditions. Results of the two studies showed that self-injury increased during the naloxone trial, whereas a decrease to near zero rates of self-injury was observed following treatment with naltrexone. The differential effect produced by the two drugs was discussed in terms of drug half-life and the operant conditioning theory of extinction. Follow-up data showing near zero rates of self-injury for 22 months following the conclusion of active treatment with naltrexone indicated that the intervention produced a durable result.

Autistic Disorder↗

PubMed1984

The detection of behavioral state cycles and classification of temporal structure in behavioral states.

Previous methods for the analysis of temporal structure in sleep and other state time series have described cycles, rhythms, and semi-Markov chains. Methods, however, have been subjective and arbitrary. We propose an objective system of classification for these series, based on definitions of temporal structure which are consistent with those long used in the analysis of quantitative series. An ordered sequence of statistical tests is described which classifies observed behavioral state time series into four primary categories. The system is illustrated with examples from normal infant sleep. The results show that some infant sleep series are cycles, as previously reported, some are semi-Markov chains, and some are neither. The proposed objective methods promise consistency, clarity, and a richer understanding of behaviors such as sleep.

Arousal↗

PubMed1983

Direct computer recording of premature infants and nursery care: distress following two interventions.

Prematurely born neonates are born with an immature central nervous system. Temporal associates between care-giver interventions and infant biobehavioral responses can be recorded. A new methodology for continuous naturalistic computer-assisted recording of infants in nursery care is described. To illustrate a clinical implication of this recording, an infant's responses to two seemingly contrasted care-giver interventions were analyzed: chest physical therapy and close social interaction. There was significantly increased subtle as well as gross behavioral and physiologic distress following both chest physical therapy and close social interaction when compared with base line distress incidence. Perhaps timing of interventions is as consequential as their content toward safeguarding a preterm infant's developing autonomic regulation, motor patterns, and sleep/wake state.

Computers↗

PubMedDate not supplied

Planned NLM/AHCPR large-scale vocabulary test: using UMLS technology to determine the extent to which controlled vocabularies cover terminology needed for health care and public health.

The National Library of Medicine (NLM) and the Agency for Health Care Policy and Research (AHCPR) are sponsoring a test to determine the extent to which a combination of existing health-related terminologies covers vocabulary needed in health information systems. The test vocabularies are the 30 that are fully or partially represented in the 1996 edition of the Unified Medical Language System (UMLS) Metathesaurus, plus three planned additions: the portions of SNOMED International not in the 1996 Metathesaurus Read Clinical Classification, and the Logical Observations Identifiers, Names, and Codes (LOINC) system. These vocabularies are available to testers through a special interface to the Internet-based UMLS Knowledge Source Server. The test will determine the ability of the test vocabularies to serve as a source of controlled vocabulary for health data systems and applications. It should provide the basis for realistic resource estimates for developing and maintaining a comprehensive "standard" health vocabulary that is based on existing terminologies.

Computer Communication Networks↗