Issues in the Structuring and Acquisition of an Ontology for Medical Language Understanding

this paper, we examine some methodological and theoretical principles to enforce this conformity. These principles result from our experience in Menelas, a medical language understanding project

Structuration and acquisition of medical knowledge. Using UMLS in the conceptual graph formalism.

The use of a taxonomy, such as the concept type lattice (CTL) of Conceptual Graphs, is a central structuring piece in a knowledge-based system. The knowledge it contains is constantly used by the system, and its structure provides a guide for the acquisition of other pieces of knowledge. We show how UMLS can be used as a knowledge resource to build a CTL and how the CTL can help the process of acquisition for other kinds of knowledge. We illustrate this method in the context of the MENELAS natural language understanding project

Hypertextual navigation operationalizing generic clinical practice guidelines for patient-specific therapeutic decisions.

Despite the proliferation of implemented clinical practice guidelines, there is still little evidence of physicians compliance to formal standards. The ONCODOC project proposes a framework for elaborating generic decision support guidelines in a document-based paradigm with a knowledge-based approach. It has been first applied to assist clinicians in the treatment of breast cancer patients. Therapeutic expertise has been encoded as a decision tree. The decision process is driven by the clinician who interactively browses a hypertext version of the decision tree. During the navigation, he incrementally assigns values to decision parameters on the basis of his free interpretation of his patient's condition and thus builds a clinical context leading to patient-specific therapeutic recommendations. These guidelines are distributed on a hospital intranet and are evaluated at the point of care in an oncology department

Hospitexte: towards a document-based Hypertextual Electronic Medical Record

INTRODUCTION Documents are the core of medical reflection: in a Paperbased Medical Record (PMR), we found a lot (typically 150-200) of documents which give to the health-care professional board all the information necessary to follow up and treat the patient. These documents are of different natures (paper, image, etc) and come from different sources (laboratories, clinical departments, etc). Moreover, laboratory results come with textual reports which give important information about the exam. Assuming that we want to change the support of the PMR for an Electronic Medical record (EMR), few effective technologies may propose an appropriate solution. In a traditional approach which tends to formalize knowledge, a view of the EMR is that of a database which holds items of coded, or standardized, information. In a different way, effective technologies like hypertext offer an opportunity to develop new systems based on the concept of "document processing". Our claim is that if w

Lack of cadherins Celsr2 and Celsr3 impairs ependymal ciliogenesis, leading to fatal hydrocephalus

Ependymal cells form the epithelial lining of cerebral ventricles. Their apical surface is covered by cilia that beat in a coordinated fashion to facilitate circulation of the cerebrospinal fluid (CSF). The genetic factors that govern the development and function of ependymal cilia remain poorly understood. We found that the planar cell polarity cadherins Celsr2 and Celsr3 control these processes. In Celsr2-deficient mice, the development and planar organization of ependymal cilia are compromised, leading to defective CSF dynamics and hydrocephalus. In Celsr2 and Celsr3 double mutant ependyma, ciliogenesis is markedly impaired, resulting in lethal hydrocephalus. The membrane distribution of Vangl2 and Fzd3, two key planar cell polarity proteins, was disturbed in Celsr2 mutants, and even more so in Celsr2 and Celsr3 double mutants. Our findings suggest that planar cell polarity signaling is involved in ependymal cilia development and in the pathophysiology of hydrocephalus, with possible implications in other ciliopathies

Ciliogenesis defects in embryos lacking inturned or fuzzy function are associated with failure of planar cell polarity and Hedgehog signaling

The vertebrate planar cell polarity (PCP) pathway has previously been found to control polarized cell behaviors rather than cell fate. We report here that disruption of Xenopus laevis orthologs of the Drosophila melanogaster PCP effectors inturned (in) or fuzzy (fy) affected not only PCP-dependent convergent extension but also elicited embryonic phenotypes consistent with defective Hedgehog signaling. These defects in Hedgehog signaling resulted from a broad requirement for Inturned and Fuzzy in ciliogenesis. We show that these proteins govern apical actin assembly and thus control the orientation, but not assembly, of ciliary microtubules. Finally, accumulation of Dishevelled and Inturned near the basal apparatus of cilia suggests that these proteins function in a common pathway with core PCP components to regulate ciliogenesis. Together, these data highlight the interrelationships between cell polarity, cellular morphogenesis, signal transduction and cell fate specification.close19419