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Biomedical subjects

M S Tuttle

Publications and source records attributed to M S Tuttle.

At least 19 recordsLinked to original sources
PubMed1994

The role of the UMLS in 'storing' and 'sharing' across systems.

We will argue that 'sharing', 're-use', 're-purposing', and 'addition' of health care information is difficult, intrinsically; that the best way to overcome the difficulty is to start doing it, as soon as possible, and that the UMLS Knowledge Sources provide the best place to start. We recommend that the UMLS be used as a default source of biomedical concept names and relationships, as a comprehensive, data-based, 'reference model', and as an example of a large, ecumenical, evolving, continuously updated source of re-usable health care information.

Computer User Training↗
PubMed1994

Formal properties of the Metathesaurus.

The Metathesaurus is a machine-created, human edited and enhanced synthesis of authoritative biomedical terminologies. Its formal properties permit it to be a) exploited by computers, and b) modified and enhanced without compromising that usage. If further constraints were imposed on the existence and identity of Metathesaurus relationships, i.e., if every Metathesaurus concept had a "genus" and a "differentia," then the Metathesaurus could be converted into an "Aristotelian Hierarchy." In this sense, a genus is a concept that classifies another concept, and a differentia is a concept that distinguishes the classified concept from all other concepts in the same class. Since, in principle, these constraints would make the Metathesaurus easier to leverage and maintain computationally, it is interesting to ask to what degree the maintenance and enhancement procedures now in place are producing a Metathesaurus that is also an "Aristotelian Hierarchy." Given a liberal interpretation of the current Metathesaurus schema, the proportion of the Metathesaurus that is "Aristotelian" in each annual version is increasing in spite of dramatic concurrent increases in the number of Metathesaurus concepts. Without formality there is no modifiability nor scalability. [1] We need formal methods and computer-based tools that can help us with the task [of controlled medical vocabulary construction]. We need research in which controlled vocabulary development is the focus rather than a stepping stone for work on other theories and applications. [2]

Subject Headings↗
PubMed1993

Recognizing new medical knowledge computationally.

Can new medical knowledge be recognized computationally? We know knowledge is changing, and our knowledge-based systems will need to accommodate that change in knowledge on a regular basis if they are to stay successful. Computational recognition of these changes seems desirable. It is unlikely that low level objects in the computational universe, bits and characters, will change much over time, higher level objects of language, where meaning begins to emerge, may show change. An analysis of ten arbitrarily selected paragraphs from the Medical Knowledge Self-Assessment Program of the American College of Physicians was used as a test bed for nominal phrase recognition. While there were words not known to Meta-1.2, only 8 of the 32 concepts new to the primary author were pointed to by new words. Use of a barrier word method was successful in identifying 23 of the 32 new concepts. Use of co-occurrence (in sentences) of putative nominal phrases may reduce the amount of human effort involved in recognizing the emergence of new relationships.

Artificial Intelligence↗
PubMed1993

Toward an interim standard for patient-centered knowledge-access.

Most care-giver "knowledge" needs arise at the point of care and are "patient-centered." Many of these knowledge needs can be met using existing on-line knowledge sources, but the process is too time-consuming, currently, for even the computer-proficient. We are developing a set of public domain standards aimed at bringing potentially relevant knowledge to the point of care in a straight-forward and timely fashion. The standards will a) make use of selected items from a Computer-based Patient Record (CPR), e.g., a diagnosis and measure of severity, b) anticipate certain care-giver knowledge needs, e.g., "therapy," "protocols," "complications," and c) try to satisfy those needs from available knowledge sources, e.g., knowledge-bases, citation databases, practice guidelines, and on-line textbooks. The standards will use templates, i.e., fill-in-the-blank structures, to anticipate knowledge needs and UMLS Metathesaurus enhancements to represent the content of knowledge sources. Together, the standards will form the specification for a "Knowledge-Server" (KS) designed to be accessed from any CPR system. Plans are in place to test an interim version of this specification in the context of medical oncology. We are accumulating anecdotal evidence that a KS operating in conjunction with a CPR is much more compelling to users than either a CPR or a KS operating alone.

Artificial Intelligence↗
PubMed1992

The homogenization of the Metathesaurus schema and distribution format.

The third version of the UMLS Metathesaurus, Meta-1.2, to be released in October 1992, will have a simpler schema and simpler distribution formats than the first two versions, Meta-1.0 and Meta-1.1 released in October 1990 and 1991, respectively. For one thing, it will have only a single kind of entry (Concept), rather than three (Concept, Related, and Synonym). Further, the Relational Format, will consist of four logical relations, or tables, instead of the nearly three score different tables used to represent the same kind of information in Meta-1.1. These four tables will contain, respectively, (1) the names of each concept, (2) the relationships between concepts, (3) attributes of the concepts, and (4) a word-based index into the concept names. We argue that the new schema and formats provide a better conceptual model of the Metathesaurus, and represent the information contained there more uniformly. Even though these changes are incremental and evolutionary, both users and software developers should find the Meta-1.2 significantly easier to understand, and the information contained in it significantly easier to use.

Information Storage and Retrieval↗
PubMed1992

The Meta-1.2 engine: a refined strategy for linking biomedical vocabularies.

This paper presents a preliminary description of the database schema and associated procedures that are the foundation for the "engine" that will produce Meta-1.2. Meta-1.2 is the next incarnation of the Metathesaurus, which is one of the principal components of the National Library of Medicine's Unified Medical Language System (UMLS). We use the word "engine" as a generic term that includes a database and the programs that operate on it. While this design builds heavily upon previous work, it incorporates some major changes in philosophy. A major hypothesis is that the simple representation described here is suitable for any controlled vocabulary in the biomedical domain. Indeed, this hypothesis is central to a strategy for producing future versions of the Metathesaurus and for supporting collaboration with people who wish to contribute additional terms and relationships to the Metathesaurus. Another change involves the representation of classes and relationships. The revised database schema includes an explicit representation of the source or "authority" for relationships, which is analogous to the way that the sources of terms have been represented since the first version of the Metathesaurus. A sequence of steps utilizing the new representations to produce the Metathesaurus is presented.

Databases, Factual↗
PubMed1992

The semantic structure of the UMLS Metathesaurus.

Meta-1.1, the UMLS metathesaurus, represents medical knowledge in the forms of names of concepts and links between those concepts. The representations of the semantic neighborhood of a concept can be thought of as dimensions of the property of semantic locality and include term information (broader, narrower, or otherwise related), the contextual information (parent-child, siblings in a hierarchy), the semantic types, and the co-occurrence data (links discovered empirically from concepts used to index the medical literature.) The degree of redundancy of each of these dimensions was investigated by reviewing the extent of multiple presentations of concepts which appear as related to a given concept. The degree of overlap was surprisingly small. While the co-occurrence data finds some of the links represented by other dimensions, those links are but minute fractions of the vast amount of co-occurrence derived links. Because parent-child relationships are often subsumptive (or categorical) in nature, it might be expected that siblings usually share the same semantic types. While true in the aggregate, the wide variance in percent of types shared may reflect the intended usages of the source vocabularies. Noun phrases were extracted from the definitions of 40 concepts in Meta-1 in order to assess systematically the coverage of important concepts by Meta-1, and to assess whether the links between these definitional concepts, which may have special value, and the concept being defined were indeed present. Out of 161 of these definitional concepts, 29 were not represented in Meta-1, and 37 of those represented in Meta-1 had no direct link to the concept they were defining.(ABSTRACT TRUNCATED AT 250 WORDS)

Semantics↗
PubMed1991

Biomedical database inter-connectivity: an experiment linking MIM, GENBANK, and META-1 via MEDLINE.

The linkage of disparate biomedical databases is an important goal of the Unified Medical Language (UMLS) Project. We conducted an experiment to investigate the feasibility of using UMLS resources to link databases in clinical genetics and molecular biology. References from MIM ("Mendelian Inheritance in Man") were lexically mapped to the equivalent citations in MEDLINE. The MeSH major subject headings by which the citations in a particular MIM entry had been indexed were used to develop a "genetic-disorder-centered view of the world" in Meta-1 (the first official version of the UMLS Metathesaurus). Our hypothesis was that these MeSH subject headings could provide access to a "semantic neighborhood" in Meta-1 that would be relevant to a particular genetic disorder. By browsing in this "semantic neighborhood," a user could select various combinations of terms with which to search MEDLINE through an interface between Meta-1 and Grateful Med. Such searches might retrieve citations that were more recent than those in MIM or that provided useful supplementary information. Since some MEDLINE records contain pointers to entries in GENBANK, information about genetic sequences related to a particular clinical genetic disorder could also be retrieved. This scenario was implemented for a small number of MIM entries, providing a concrete demonstration that linking disparate electronic databases in an important subdomain of biomedicine is relatively straightforward.

Databases, Factual↗
PubMed1991

From meaning to term: semantic locality in the UMLS Metathesaurus.

The Unified Medical Language System Metathesaurus represents the results of a synthesis of existing biomedical naming systems (thesauri). The naming and other information about the meanings in the Metathesaurus can be used to find the preferred naming of that meaning in the source chosen by the user, by exploiting the property of semantic locality. The aspects of semantic locality in the Metathesaurus which can be thus exploited are the terms, the semantic types, the use of that term in a source context, and the co-occurrence of terms in MEDLINE. To find how a meaning is named in the source of choice, a user must exploit one of these aspects of semantic locality, entering a term somehow related to the term being sought, and navigating to the preferred term. While the first three of these aspects of semantic locality are normative, the last is empirical. Testing of the utility of the aspects of semantic locality in information retrieval would require a uniform interface with 1, no Metathesaurus, 2, the Metathesaurus without the aspects in question, and 3, the Metathesaurus including all the aspects. Other potential uses of empirically derived semantic locality include defining or suggesting potentially relevant concepts in a given situation.

Semantics↗
PubMed1991

Adding your terms and relationships to the UMLS Metathesaurus.

The National Library of Medicine's Unified Medical Language System [1] Metathesaurus contains the richest single corpus of biomedical names in existence. Yet, developers wishing to make use of the Metathesaurus will be confronted by users who want to add local terminology and relationships not already represented there. We urge developers to fill those needs, while, at the same time, they plan for the many consequences of unilateral Metathesaurus enhancement. Foremost among these consequences is the need to maintain local enhancements across subsequent releases of the Metathesaurus. These problems are illustrated via examples of candidate Metathesaurus enhancement terms in use at the Columbia-Presbyterian Medical Center (CPMC), at the Mayo Clinic, and in Current Disease Descriptions (CDD). Sharing and reuse of Metathesaurus enhancement methods may permit local enhancements to be used at other sites, and it may permit the global Metathesaurus utilization effort to benefit from economies of scale.

Terminology as Topic↗
PubMed1985

Evaluating RECONSIDER. A computer program for diagnostic prompting.

RECONSIDER, a computer program designed to perform as a diagnostic prompting aid, was evaluated for its ability to include the correct diagnosis in an ordered computed list of candidate diseases. The study was performed using 100 consecutive first admissions to the medical service of a university hospital, where the individuals entering the data into the program were blind to all but a limited set of findings known at time of admission. Each person entering the data created one or more lists of diagnostic possibilities (versions) using the program. The program suggested the correct diagnosis within the first 40 on its list 61% (498/797) of the time; the correct diagnosis was present with the first 40 in at least one version 93% (98/105) of the time. Performance was found to be best with cases having a single diagnosis and when more terms were entered into the program.

Computers↗
PubMed1983

Malignant melanoma of the skin. I. The association of tumor depth and type, and patient sex, age, and site with survival.

The occurrence and behavior of cutaneous melanomas in a group of 1123 patients studied prospectively, is described in terms of histologic type, tumor thickness and levels of invasion, the patients' sex and age, and the anatomic location of the primary tumors. Associations amongst these attributes, and with survival, are also examined. The characteristics of the patients in this study (who on average are somewhat younger, and have better prognoses and survivals than those reported by most other groups) are compared with data obtained (primarily over the past decade) in other geographical areas, and with different patient populations. Evidence is presented that sex, tumor location, and age (in the case of males) are also predictive of survival.

Adolescent↗
PubMed1983

Judging prognosis in malignant melanoma of the skin. A problem of inference over small data sets.

Data was generated for 828 clinical stage 1 melanoma patients, divided into groups according to sex, tumor location, and tumor level for each of the 56 groups. Summary data, including the number of patients, number of patients dying as a result of melanoma, range of tumor thickness, mean and median tumor thickness, and mean length of follow-up of the surviving patients, are shown. Patients with melanoma of the palms and soles, subungual melanomas, and mucosal melanomas were excluded. A physician with a new melanoma patient could select the appropriate group for his or her patient, matched with respect to sex, location, and level, and then make a judgment regarding the prognosis, based on the survival experience of the group. In a few groups, the small numbers of patients provides only a rough impression of survival, but with many groups, a fair estimate can be made. The effectiveness of elective lymph node dissection was examined by creating 111 pairs of patients, matched by sex, level, location, and tumor thickness (to within +/- 12%), in which one member of the pair had an elective node dissection (ELND) and the other did not. There was no statistically significant difference between the survival of the two groups.

Female↗