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At least 397 records · Page 22Linked to original sources

PubMed1985

INTERNIST-I properties: representing common sense and good medical practice in a computerized medical knowledge base.

INTERNIST-I is an experimental diagnostic consultant program for use on clinically challenging cases in internal medicine. Properties are a part of the INTERNIST-I knowledge representation scheme which embody essential information about the medical facts contained in the knowledge base. Properties provide the INTERNIST-I program with a measure of common sense and encourage the program to follow good medical practice. Properties substantially influence the behavior of the INTERNIST-I diagnostic program during case analyses. This paper reviews the implementation and significance of properties.

Artificial Intelligence↗

PubMed1991

["INTENSIV"--organization and structure of a knowledge-based PC system for the intensive care unit].

A computer program for use on an intensive care unit (ICU) has been developed. The program INTENSIV is a knowledge-based system with integrated conventional basic functions. Besides managing all patient-related data, the program processes all laboratory data, clinical observations and measured data. Deviations from the norm and disturbances in patient balances are recognized by the system; under consideration of contraindications such as antagonistic or synergistic drug interactions, the system makes recommendations for basic therapy regimens as well as necessary corrections according to changes in the regular course of an illness. Aside from disturbance analysis and therapy planning, the computer can portray and document the entire course of therapy and the patient's progress as seen in ICU charts, including fluid and electrolyte balances and graphic parameter curves.

Database Management Systems↗

PubMed1997

A knowledge base for D. melanogaster gene interactions involved in pattern formation.

The understanding of pattern formation in Drosophila requires the handling of the many genetic and molecular interactions which occur between developmental genes. For that purpose, a knowledge base (KNIFE) has been developed in order to structure and manipulate the interaction data. KNIFE contains data about interactions published in the literature and gathered from various databases. These data are structured in an object knowledge representation system into various interrelated entities. KNIFE can be browsed through a WWW interface in order to select, classify and examine the objects and their references in other bases. It also provides specialised biological tools such as interaction network manipulation and diagnosis of missing interactions.

Animals↗

PubMed1995

Computerized knowledge bases in primary health care: a curse or a blessing for health promotion, prevention and patient quality?.

This paper presents a future scenario analysis of how the introduction of computerized knowledge bases (KBs) can come to affect primary care practice. For the collection and analysis of data, a two-level video method was applied. First, four consultations where a computerized KB was used were video-recorded. A search workshop was then carried out by letting a multi-disciplinary panel comment on the video recordings. The comments were categorized with regard to content and perspective. Analyses of the comments showed a concern for a disregard of patients' health beliefs and for difficulties in portioning out the acquired medical knowledge to the patient during the consultation. Furthermore, the computerized KB was found to easily break the natural flow of the consultation and be perceived as a third party. The conclusion is that the most critical aspects for using computerized KBs in a reformed primary health care concern the integration of the systems into the consultation process. Health promotion, prevention, and patient quality are central here, and the introduction of KB technology must not lead the consultation away from these issues.

Artificial Intelligence↗

PubMed2001

A knowledge-based boundary delineation system for contrast ventriculograms.

Automated left-ventricle (LV) boundary delineation from contrast ventriculograms has been studied for decades. Unfortunately, no accurate methods have ever been reported. A new knowledge based multistage method to automatically delineate the LV boundary at end diastole (ED) and end systole (ES) is discussed in this paper. It has a mean absolute boundary error or about 2 mm and an associated ejection fraction error of about 6%. The method makes extensive use of knowledge about LV shape and movement. The processing includes a multiimage pixel region classification, shape regression, and rejection classification. The method was trained and cross-validated tested on a database of 375 studies whose ED and ES boundary had been manually traced as the ground truth. The cross-validated results presented in this paper show that the accuracy is close to and slightly above the interobserver variability.

Artificial Intelligence↗

PubMed1998

Patients' views of quality of life: transforming the knowledge base of nursing.

Nurses in advanced practice roles are leaders of the transformative process that will further define the discipline of nursing as a human science of lived experience. Essential to the transformation is a change in nursing's knowledge base, a change that defines practice and research as participative, open, and quality enhancing. To demonstrate the transformation of knowledge in practice, the authors present findings from a qualitative research study guided by the nursing theory called human becoming. The purpose of the study was to enhance understanding of quality of life for patients receiving acute psychiatric care. A descriptive exploratory design was used to guide data gathering and analysis of 24 people. Findings are presented in themes that represent quality-of-life issues, including feelings of loss and shifting value priorities, the complex nature of relationships that ease and upset, and the hopes that fuel the intense struggle to go on living. Directions for practice and research are suggested.

Adult↗

PubMed1999

Mapping of putative binding sites on the ectodomain of the type II TGF-beta receptor by scanning-deletion mutagenesis and knowledge-based modeling.

Binding surfaces of the type II transforming growth factor (TGF)-beta receptor extracellular domain (TbetaRII-ECD) are mapped by combining scanning-deletion mutagenesis results with knowledge-based modeling of the ectodomain structure. Of the 17 deletion mutants produced within the core binding domain of TbetaRII-ECD, only three retained binding to TGF-beta. Comparative modeling based on the crystal structure of the activin type II receptor extracellular domain (ActRII-ECD) indicates that the TbetaRII mutants which retain TGF-beta binding are deleted in some of the loops connecting the beta-strands in the TbetaRII-ECD model. Interpretation of the mutagenesis data within the structural framework of the ectodomain model allows for the prediction of potential binding sites at the surface of TbetaRII-ECD.

Amino Acid Sequence↗

PubMed1988

18th Sir Hans Krebs lecture. Knowledge-based protein modelling and design.

A systematic technique for protein modelling that is applicable to the design of drugs, peptide vaccines and novel proteins is described. Our approach is knowledge-based, depending on the structures of homologous or analogous proteins and more generally on a relational data base of protein three-dimensional structures. The procedure simultaneously aligns the known tertiary structures, selects fragments from the structurally conserved regions on the basis of sequence homology, aligns these with the 'average structure' or 'framework', builds on the loops selected from homologous proteins or a wider database, substitutes sidechains and energy minimises the resultant model. Applications to modelling an homologous structure, tissue plasminogen activator on the basis of another serine proteinase, and to modelling an analogous protein, HIV viral proteinase on the basis of aspartic proteinases, are described. The converse problem of ab initio design is also addressed: this involves the selection of an amino acid sequence to give a particular tertiary structure, in this case a symmetrical domain of two Greek-key motifs.

Base Sequence↗

PubMed1994

Designing a sub-set of the UMLS knowledge base applied to a clinical domain: methods and evaluation.

The UMLS is a complex collection of interconnected biomedical concepts derived from standard nomenclatures. Designing a specific subset of the UMLS knowledge base relevant to a medical domain is a prerequisite for the development of specialized applications based on UMLS. We have developed a method based on the selection of the appropriate terms in original nomenclatures and the capture of a set of UMLS terms that are linked to them in the network to a certain degree. We have experimented it as the foundation for a concept base applied to urology. Results depend on the exhaustiveness of the relationships between the Metal concepts. A preliminary analysis of the sub-base reveals that some adaptations of vocabulary and ontology are required for clinical applications.

Algorithms↗

PubMed1998

Evolution of a knowledge base for a clinical decision support system encoded in the Arden Syntax.

Clinical decision support systems (CDSS) are being used increasingly in medical practice. Thus, long-term maintenance of the knowledge bases (KB) of such systems becomes important. To quantify changes that occur as a KB evolves, we studied the KB at the Columbia-Presbyterian Medical Center. This KB has a total of 229 Medical Logic Modules (MLMs) encoded in the Arden Syntax. Eliminating those never used in practice, we retrospectively analyzed 156 MLMs developed over 78 months. We noted 2020 distinct versions of these MLMs that included 5528 changed statements over time. These changes occurred primarily in the logic slot (38.7% of all changes), the action slot (17.8%), in queries (15.0%) and in the data slot exclusive of queries (12.4%). We conclude that long-term maintenance of a KB for a CDSS requires significant changes over time. We discuss the implications of these results for the design of KB editors for the Arden Syntax.

Artificial Intelligence↗

PubMed1998

Assessing an AI knowledge-base for asymptomatic liver diseases.

Discovering not yet seen knowledge from clinical data is of importance in the field of asymptomatic liver diseases. Avoidance of liver biopsy which is used as the ultimate confirmation of diagnosis by making the decision based on relevant laboratory findings only, would be considered an essential support. The system based on Quinlan's ID3 algorithm was simple and efficient in extracting the sought knowledge. Basic principles of applying the AI systems are therefore described and complemented with medical evaluation. Some of the diagnostic rules were found to be useful as decision algorithms i.e. they could be directly applied in clinical work and made a part of the knowledge-base of the Liver Guide, an automated decision support system.

Algorithms↗

PubMed2005

DrugScore(CSD)-knowledge-based scoring function derived from small molecule crystal data with superior recognition rate of near-native ligand poses and better affinity prediction.

Following the formalism used for the development of the knowledge-based scoring function DrugScore, new distance-dependent pair potentials are obtained from nonbonded interactions in small organic molecule crystal packings. Compared to potentials derived from protein-ligand complexes, the better resolved small molecule structures provide relevant contact data in a more balanced distribution of atom types and produce potentials of superior statistical significance and more detailed shape. Applied to recognizing binding geometries of ligands docked into proteins, this new scoring function (DrugScore(CSD)) ranks the crystal structures of 100 protein-ligand complexes best among up to 100 generated decoy geometries in 77% of all cases. Accepting root-mean-square deviations (rmsd) of up to 2 angstroms from the native pose as well-docked solutions, a correct binding mode is found in 87% of the cases. This translates into an improvement of the new scoring function of 57% with respect to the retrieval of the crystal structure and 20% with respect to the identification of a well-docked ligand pose compared to the original Protein Data Bank-based DrugScore. In the analysis of decoy geometries of cross-docking studies, DrugScore(CSD) shows equivalent or increased performance compared to the original PDB-based DrugScore. Furthermore, DrugScore(CSD) predicts binding affinities convincingly. Reducing the set of docking solutions to examples that deviate increasingly from the native pose results in a loss of performance of DrugScore(CSD). This indicates that a necessary prerequisite to successfully resolving the scoring problem with a more discriminative scoring function is the generation of highly accurate ligand poses, which approximate the native pose to below 1 angstroms rmsd, in a docking run.

Crystallography, X-Ray↗

PubMed1998

The effect of a knowledge-based, image analysis and clinical decision support system on observer performance in the diagnosis of approximal caries from radiographic images.

The aim of this study was to investigate the effect of a knowledge-based image analysis and clinical decision support system (CariesFinder, CF) on diagnostic performance and therapeutic decisions. The study material consisted of radiographic images of 102 approximal surfaces, 35 sound, 67 caries (25 caries and cavitated and 42 caries). Sixteen general practitioners were presented with (1) radiographic film images and (2) digital filmless images with the results of CF. The viewers were asked to respond whether approximal caries was present and whether a restoration was indicated. Responses were analyzed for accuracy, sensitivity, specificity and agreement. Further, the practitioners were ranked according to the accuracy of their restorative decisions and assigned to ten overlapping groups of 7 practitioners. For each group the diagnostic and therapeutic decisions were then examined for unanimity. The parameters of accuracy, sensitivity and specificity were then established for each group based on only unanimous, correct decisions. The diagnostic and therapeutic accuracy of CF alone was equal or superior to the decisions of the practitioners viewing film images alone. For unanimous decisions, CF alone was more accurate than the most accurate group of practitioners and made fewer incorrect decisions to restore non-cavitated surfaces than the practitioners. In general, dental practitioners viewing the results of CF significantly increased their ability to diagnose caries correctly, their overall diagnostic accuracy, and their ability to recommend restorations for cavitated surfaces. There was a decrease in the accuracy of their restorative decisions overall and in the specificity in particular.

Analysis of Variance↗

PubMed1993

Computerized design of removable partial dentures: a knowledge-based system for the future.

Dentists frequently fail to provide dental technicians with the design information necessary for the construction of removable partial dentures. The computerization of dental practices and the development of appropriate knowledge-based systems could provide a powerful tool for improving this aspect of dental care. This article describes one such system currently under development which is an example of the kind of additional facility that will become available for those practices with the necessary hardware.

Artificial Intelligence↗

PubMedDate not supplied

Knowledge-based understanding of radiology text.

A data acquisition tool which will extract pertinent diagnostic information from radiology reports has been designed and implemented. Pertinent diagnostic information is defined as that clinical data which is used by the HELP medical expert system. The program uses a memory-based semantic parsing technique to 'understand' the text. Moreover, the memory structures and lexicon necessary to perform this action are automatically generated from the diagnostic knowledge base by using a special purpose compiler. The result is a system where data extraction from free text is directed by an expert system whose goal is diagnosis.

Computer-Assisted Instruction↗

PubMed1995

A knowledge-based model of DNA hydration.

The aqueous hydration of DNA is an important aspect of its structure, which is of direct relevance to mechanisms of radiation damage. We have made a quantitative analysis of solvent interactions within hydrogen bonding distance of polar atoms of oligonucleotides using 12 B-DNA oligonucleotide crystal structures. The distribution of water molecules around the four bases, the sugar residues and the phosphate groups were generated and analysed both qualitatively and quantitatively. These data have then been used in a knowledge-based method to generate the likely hydration sites around a canonical B-DNA conformation in order to generate models of use in track studies of radiation damage.

Base Sequence↗

PubMed1999

Automatic enrichment of the unified medical language system starting from the ADM knowledge base.

The Unified Medical Language System (UMLS) project aims to provide a repository of terms, concepts and relationships from several medical classifications. This work describes the possibility to enrich automatically with meaningful links the UMLS database by using description of diseases from another knowledge base, in our case ADM (Aide au Diagnostic Medical). In spite of the constraints and the difficulties to qualify the interconcept links, the results show that it is possible to find and create new links from a french knowledge database to the UMLS one. One of the interests of this work is that the automated learning of the connections could be used with others knowledge databases like expert system databases.

Algorithms↗

PubMed2002

Visually- and motor-based knowledge of letters: evidence from a pure alexic patient.

We describe a patient, VSB, whose reading was impaired as a consequence of a left temporal-parietal lesion, whereas writing was relatively preserved. At variance with other pure alexic patients described in the literature, VSB claimed to have become unable to mentally visualise letters and words. Indeed, his performance on a series of tests tapping visual mental imagery for orthographic material was severely impaired. However, performance on the same tests was dramatically ameliorated by allowing VSB to trace each item with his finger. Visual mental imagery for non-orthographic items was comparatively spared. The pattern of dissociation shown by VSB between impaired visual mental imagery and relatively preserved motor-based knowledge for orthographic material lends support to the view that separate codes, respectively based on visual appearance and on motor engrams, may be used to access knowledge of the visual form of letters and words.

Alexia, Pure↗