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Biomedical subjects

W D Sperzel

Publications and source records attributed to W D Sperzel.

13 recordsLinked to original sources
PubMed1998

The future of knowledge-based components in the electronic health record.

Traditional monolithic healthcare information systems (HIS) no longer meet the requirements of today's distributed enterprises and the rapidly changing healthcare environment. The ability of applications to communicate, interpret, and act intelligently upon complex healthcare information has assumed paramount importance. The future lies in the development of flexible component-based architectures that can operate seamlessly within the workflow of a healthcare environment. A key design goal is "graceful degradation," i.e., providing the best decision support possible within the context of available patient data. The First DataBank Drug Toolkit is used as a case study. Several technical challenges associated with building truly plug and play components are discussed.

Artificial Intelligence↗
PubMed1998

The need for a concept-based medication vocabulary as an enabling infrastructure in health informatics.

Users of drug information typically focus their attention at different levels of description in different situations, such as medication ordering or dispensing. Computer systems utilizing drug information to support such activities must accommodate these multiple perspectives. This paper presents an approach to conceptualizing drug descriptions at multiple levels and outlines key features of an underlying information model that can serve as the basis for a concept-oriented medication vocabulary. These features include dose forms, routes of administration, as well as links to multiple drug classification schemes and medical problems. Implementation, standards, and maintenance issues related to the model are also discussed.

Decision Support Systems, Clinical↗
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.)↗
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↗
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↗
PubMed1986

Clinical trials with terazosin. General methods.

Terazosin has been studied in a variety of clinical trials conducted in hypertensive patients with supine diastolic blood pressures of 95 mm Hg or greater before treatment. Blood pressure, pulse rate, body weight, clinical laboratory variables, and adverse experience data were evaluated periodically throughout each study. Patients generally were seen at weekly or biweekly intervals. Total daily doses of terazosin ranged from 1 to 40 mg. Terazosin was administered alone and in combination with other antihypertensive agents. Clinical trials consisted of double-blind, controlled studies and long-term, follow-up studies. The controlled clinical trials employed three principal designs: studies in which the dose was titrated according to blood pressure response; studies in which the dose was increased to a fixed level regardless of blood pressure response; and randomized withdrawal studies. Efficacy evaluations were based on mean blood pressure changes from baseline to the final visit and on the distribution of patient responses, which were categorized from excellent to inadequate. Safety evaluations were based principally on comparisons of specific safety parameters before and after the study.

Adolescent↗
PubMed1986

Efficacy of terazosin as an antihypertensive agent.

A total of 713 patients with hypertension were evaluated in eight randomized, double-blind, placebo-controlled trials of terazosin administered in single daily doses ranging from 1 to 40 mg. In three of these studies, terazosin or placebo was added to ongoing antihypertensive drug therapy. Patient response was categorized (from excellent to inadequate) according to the change in supine diastolic blood pressure from baseline and the value at the final visit. The distribution of patients in these response categories differed significantly between patients treated with terazosin and those treated with placebo. Overall, 52 percent of terazosin-treated patients in these eight studies, compared with 30 percent of placebo-treated patients, had good to excellent responses. Subgroup analysis revealed that blood pressure response was not dependent on sex or age, although white patients appeared to achieve better responses to terazosin in comparison with placebo than did black patients. These studies demonstrate that terazosin administered once daily, either as monotherapy or in combination with other antihypertensive agents, effectively controls blood pressure in patients with mild to moderate hypertension.

Adolescent↗
PubMed1986

Overall safety of terazosin as an antihypertensive agent.

The safety of terazosin, an effective agent for the treatment of hypertension, was assessed by analyzing data from 1,006 hypertensive patients who were enrolled in short-term and/or long-term studies. The total experience with terazosin in this article represents 422.5 patient-years. Changes in pulse rate measurements from pretreatment to posttreatment were not significantly different between the terazosin- and placebo-treated patients (-1.0 beat per minute for the terazosin group and -1.0 beat per minute for the placebo group, in the supine position). Dizziness, headache, and asthenia were the most commonly reported adverse experiences among all terazosin-treated patients, although the incidence of headache in placebo-controlled trials was not significantly different between the terazosin and placebo groups. As a whole, patients receiving terazosin had a tendency to gain small amounts of weight (2 pounds). In addition, there was a trend for slight decreases in hemoglobin, hematocrit, white blood cell count, total protein, and albumin levels in those patients who received terazosin, suggesting hemodilution. Overall, terazosin was shown to be safe in patients with mild to moderate essential hypertension.

Adolescent↗
PubMed1986

Terazosin: a new alpha 1-blocker for the treatment of hypertension: a review of randomized, controlled clinical trials of once-daily administration as monotherapy.

Terazosin, a new selective long-acting alpha1-adrenergic blocking agent, has been shown to be an effective once-daily antihypertensive agent in four of five randomized double-blind placebo-controlled studies of patients with mild to moderate hypertension. In one trial, 24-h monitoring revealed that terazosin produced a sustained blood pressure lowering effect throughout the day. In three fixed-dose trials, steady patterns of blood pressure response during maintenance therapy indicated that tolerance to terazosin did not develop. Favourable changes in the plasma lipid profile were observed, while laboratory data suggested the development of haemodilution. Overall, terazosin was well tolerated. Asthenia, dizziness and peripheral oedema were significantly more common in patients treated with terazosin than with placebo.

Adrenergic alpha-Antagonists↗