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Biomedical subjects

W Pratt

Publications and source records attributed to W Pratt.

14 recordsLinked to original sources
PubMed2003

Sociotechnical requirements analysis for clinical systems.

OBJECTIVE: We explore sociotechnical requirements by examining the use of a computerized patient record system in an intensive care unit of a U.S. hospital and present two sociotechnical requirements, awareness and coordination, embedded in the users' work. METHOD: The study is based on observation during seven months of the use of a computerized patient record system in a surgical intensive care unit. During that period semi-formal interviews, informal interviews were held. RESULTS AND CONCLUSIONS: A key step in the design of clinical systems is the development and analysis of requirements. However, traditional requirements analysis is based on a set of assumptions that break down in the highly collaborative, exception-filled clinical domain. Sociotechnical requirement analysis enabled the designers to gather a much richer description of the environment surrounding the computer system, highlighting awareness and coordination, embedded in the users' work.

Cooperative Behavior↗
PubMed2002

Hallucinogens and Drosophila: linking serotonin receptor activation to behavior.

The similarity of mode of action, behavior, and gene response between Drosophila melanogaster and mammalian systems, combined with the power of genetics, have recently made the fly an attractive system to study underlying mechanisms of drug abuse, addiction, and mental disorders. The present studies define the behavioral and molecular effects of the powerful hallucinogen lysergic acid diethylamide in Drosophila. Pharmacological activation of serotonin receptors in the fly by lysergic acid diethylamide induces behaviors not unlike those observed in mammalian systems. These include alterations in visual processing abilities, reduced locomotor activity, and altered gene expression within the brain. Many of these effects are due to activation of the same serotonin receptor subtypes that are thought to be the primary mediators of hallucinogenic drug effects in humans as well as the acute symptoms of schizophrenia.We suggest that Drosophila can be used as a genetically tractable model system to define the molecular events leading from serotonin receptor activation to behavior, possibly revealing new targets for hallucinogenic agents and for the treatment of neuropsychiatric disorders such as schizophrenia.

Animals↗
PubMed2000

Improved mucosal protection against Venezuelan equine encephalitis virus is induced by the molecularly defined, live-attenuated V3526 vaccine candidate.

The genetically engineered, live-attenuated Venezuelan equine encephalitis (VEE) virus vaccine candidate, V3526, was evaluated as a replacement for the TC-83 virus vaccine. Protection from lethal subcutaneous or aerosol challenge was evaluated in vaccinated mice clinically and immunohistochemically. Subcutaneous administration of V3526 induced systemic and mucosal protection more efficiently than did the TC-83 vaccine. The bronchial IgA responses induced in mice by subcutaneous administration of vaccines significantly corresponded to the ability to survive aerosol challenge with virulent virus. Furthermore, V3526 delivered by aerosol induced more complete mucosal protection than either vaccine administered subcutaneously. The ability of V3526 to induce protection in mice warrants its consideration for further testing as a potential vaccine candidate for human use.

Aerosols↗
PubMed2000

Multiple categorization of search results.

The number of publications available to physicians and patients is increasing at an alarming rate. Although users can use tools to assist in reformulating their query, this approach is ineffective when their information needs are imprecise or many documents are relevant. The ranked list presentation of documents provides little or no information relating documents to the initial query or to each other. We argue that information overload can be reduced if documents are placed in categories that (a) relate to the initial query and (b) contain a manageable number of documents. Dynamic Categorization is a knowledge-based approach that satisfies (a), however the number of documents in a category may still be large. We demonstrate that using the same approach to re-categorize the documents in large categories reduces the number of documents in the subcategory, and maintains a clear relationship to the initial query.

Breast Neoplasms↗
PubMed2000

QueryCat: automatic categorization of MEDLINE queries.

A searcher's inability to formulate an appropriate query can result in an overwhelming number of retrieved documents. Our approach to this problem is to use information about common types or categories of queries to (1) reformulate the user's initial query and (2) create an informative organization of the retrieved documents from the reformulated query. To achieve these goals, we first must identify which common categories or types of queries are the best abstraction of the user's specific query. In this paper, we describe a system that performs this first step of categorizing the user's query. Our system uses a two-phased approach: a lexical analysis phase, and a semantic analysis phase. An evaluation of our system demonstrates that its query categorization corresponds reasonably well to the query categorizations by medical librarians and physicians.

Algorithms↗
PubMed1998

A microsatellite within the MUC1 locus at 1q21 is altered in the neoplastic cells of breast cancer patients.

Paired DNA samples from the neoplastic and nonneoplastic cells of 118 patients with the sporadic, nonfamilial form of breast cancer were analyzed for evidence of genetic alteration at a polymorphic microsatellite mapped to intron 6 within the MUC1 gene at 1q21. Two other microsatellite loci, D1S104 and APO-A2, which also map to 1q21, were analyzed as well. The frequency of alteration at the microsatellite within the MUC1 locus was significantly higher than D1S104 or APO-A2 (P < 0.001). Analysis by Southern blotting of the VNTR region of the MUC1 gene revealed an amplification of one allele in 34 of 54 informative cases (63%). There was no significant association between these alterations and alterations of the microsatellite within the same locus, suggesting independent mechanisms were responsible for the genetic changes. Microsatellite loci D17S579 at 17q21, the site of the BRCA1 gene, and D18S34 at 18q21-qter, the deleted in colorectal cancer locus, were also analyzed by PCR. Alterations at D17S579 and D18S34 were detected in 18.8% and 6.2% of patients, respectively (P < 0.001, and P < 0.1 relative to the frequency of alteration at D1S104 or APO-A2). A previously described polymorphism of hMSH2 was altered in 16.4% of cases.

Breast Neoplasms↗
PubMed1997

Venezuelan equine encephalitis virus vaccines induce mucosal IgA responses and protection from airborne infection in BALB/c, but not C3H/HeN mice.

Immunization with either a live-attenuated (TC-83) or formalin-inactivated (C-84) vaccine for Venezuelan equine encephalitis (VEE) virus protected BALB/c mice from lethal VEE infection acquired subcutaneously or by aerosol. While vaccinated C3H/HeN mice were also protected from parenteral infection, neither vaccine protected these mice from an aerosol infection. The apparent vaccine failures in C3H/HeN mice could not be attributed to deficiencies in virus-neutralizing antibodies in serum, as these responses were typically of equal or higher titer than those observed in protected BALB/c mice before challenge. IgG subclass analysis offered no facile explanation: profiles of IgG2 alpha dominance were observed in C3H/HeN mice given either vaccine and in BALB/c mice given the live-attenuated vaccine, whereas BALB/c antibody responses shifted toward IgGl dominance after immunization with the killed C-84 vaccine. Data from immunized congenic mice showed that the H-2 genes from the C3H/He mice were not singularly responsible for the inability of these mice to resist aerosol infection with VEE virus. VEE virus-specific IgA responses were detected more frequently in respiratory and vaginal secretions obtained from the protected BALB/c mice.

Administration, Oral↗
PubMed1997

Dynamic organization of search results using the UMLS.

When people search the medical literature, they often are overwhelmed by the large number of documents retrieved. Many systems try to solve this problem by helping the user formulate a more specific search strategy. However, when users do not have a more specific question, they need tools to help them explore and understand the results, rather than to eliminate a portion of those results. This paper describes an approach that addresses this need by automatically grouping the results of a broad search into meaningful categories based on the user's query. This approach combines the main benefit of clustering techniques with the main benefit of classification techniques by taking advantage of the domain knowledge present in the UMLS. I present a preliminary evaluation that demonstrates that a categorization produced by this approach corresponds reasonably well to a physician's categorization.

Computer Systems↗
PubMed1995

A web-based architecture for a medical vocabulary server.

For health care providers to share computing resources and medical application programs across different sites, those applications must share a common medical vocabulary. To construct a common vocabulary, researchers must have an architecture that supports collaborative, networked development. In this paper, we present a web-based server architecture for the collaborative development of a medical vocabulary: a system that provides network services in support of medical applications that need a common, controlled medical terminology. The server supports vocabulary browsing and editing and can respond to direct programmatic queries about vocabulary terms. We have tested the programmatic query-response capability of the vocabulary server with a medical application that determines when patients who have HIV infection may be eligible for certain clinical trials. Our emphasis in this paper is not on the content of the vocabulary, but rather on the communication protocol and the tools that enable collaborative improvement of the vocabulary by any network-connected user.

Computer Communication Networks↗
PubMed1995

Physician's information customizer (PIC): using a shareable user model to filter the medical literature.

The practice of medicine is information-intensive. From reviewing the literature to formulating therapeutic plans, each physician handles information differently. Yet rarely does a representation of the user's information needs and preferences--a user model--get incorporated into information management tools, even though we might reasonably expect better acceptance and effectiveness if the tools' presentation and processing were customized to the user. We developed the Physician's Information Customizer (PIC), which generates a shareable user model that can be used in any medical information-management application. PIC elicits the stable, long-term attributes of a physician through simple questions about her specialty, research focus, areas of interest, patient characteristics (e.g., ages), and practice locale. To show the utility of this user model in customizing a medical informatics application, PIC custom-filters and ranks articles from Medline, using the user model to determine what would be most interesting to the user. Preliminary evaluation on all 99 unselected articles from a recent issue of six prominent medical journals shows that PIC ranks 66% of the articles as the user would. This demonstrates the feasibility of using easily acquired physician attributes to develop a user model that can successfully filter articles of interest from a large undifferentiated collection. Further testing and development is required to optimize the custom filter and to determine which characteristics should be included in the shareable user model and which should be obtained by individual applications.

Algorithms↗
PubMed1994

Surgical planning using three-dimensional imaging and computer modeling.

The acquisition, processing, and use of three-dimensional (3D) imaging provide new insights into normal and abnormal craniofacial anatomy. In this article, characteristics of CT and MRI scanning are reviewed along with the methods used to delineate tissues and produce 3D patient displays, including contouring, shaded surface, and volumetric processing. The use of 3D model fabrication for surgical planning is discussed with examples of the production of a custom CT-based auricle model and the use of rapid prototyping technology to create models for custom alloplastic implant surgery. The review concludes with some speculation about the future of 3D medical imaging as it will influence surgical training and practice over the coming decades.

Diagnostic Imaging↗
PubMed1992

Regional localization of the intestinal mucin gene MUC3 to chromosome 7q22.

The gene MUC3 which codes for a mucin expressed in intestine (Gum et al. 1990) has previously been mapped, using somatic cell hybrids, to chromosome 7. We describe here the regional localization of MUC3 to chromosome 7q22 by in situ hybridization. Preliminary linkage analysis using CEPH (Centre d'Etude du Polymorphisme Humain) families supports this assignment and places MUC3 in the same linkage group as COL1A2 and CFTR.

Amino Acid Sequence↗
PubMedDate not supplied

The usefulness of dynamically categorizing search results.

OBJECTIVE: The authors' goal was to determine whether dynamic categorization, a new technique for organizing search results, is more useful than the two existing organizational techniques: relevance ranking and clustering. They define a useful tool as one that helps users learn about the kinds of information that pertain to their query, find answers to their questions efficiently and easily, and feel satisfied with their search experience. DESIGN: Fifteen patients with breast cancer and their family members completed query-related tasks using all three tools. The authors measured the time it took the subjects to accomplish their tasks, the number of answers to the query that the subjects found in four minutes, and the number of new answers that they could recall at the end of the study. Subjects also completed a user-satisfaction questionnaire. RESULTS: The results showed that patients with breast cancer and their family members could find significantly (P: < 0.05) more answers in a fixed amount of time and were significantly (P: < 0.05) more satisfied with their search experience when they used the dynamic categorization tool than when they used either the cluster tool or the ranking tool. Subjects indicated that the dynamic categorization tool provided an organization of search results that was more clear, easy to use, accurate, precise, and helpful than those of the other tools. CONCLUSION: The experiments indicate that dynamic categorization is an effective and useful approach for organizing search results. Tools that use this technique will help patients and their families gain quick and easy access to important medical information.

Algorithms↗