Approach to automation in immunohistochemistry

The introduction of immunochemical techniques into the routine pathology laboratory has significantly expanded the capabilities of the pathologist in diagnostic procedures. Immunostaining represents a powerful diagnostic tool in the identification and localization of cellular antigens, in paraffin sections, frozen tissues and cell preparations. The labeled-streptavidin-biotin method provides excellent sensitivity and performance. This multistep procedure includes: incubation of the slide with primary antibody, reaction with the biotinylated secondary antibody, binding with an enzyme conjugated streptavidin and revelation with chromogen substrate. Evaluation of the finished product is directly dependent on the quality of the technique. The main critical steps of this manual method are reagents application, incubation times and rinsing. These steps could be accessible to automation. Automation in immunohistochemistry could guarantee a continuous quality of labelling in improving standardisation, optimization and traceability of operations. The required qualifications are analytical flexibility, low cost, walkaway operation, user-friendly interface and biosafety.

[Galen vein aneurysm. Review of the literature and report of 2 cases]

Aneurysm of the vein of Galen is a rare congenital disease, with a generally poor prognosis. It represents less than 1% of cerebral arteriovenous malformations. The intrauterine diagnosis of this vascular anomaly has been facilitated by vascular exploration with pulsed and color Doppler sonography. According to some studies focused on prognostical criteria, the perinatal prognosis seems to be invariably compromised when signs of cardiac decompensation develop prenatally, knowing that early delivery may generate additional complications in the very premature infant. Medical treatment is inefficient, because of the large, persisting systemic shunt, so that pregnancy termination may be performed, after parental consent, in some cases demonstrating all signs of cardiac decompensation. On the other hand, infants with normal velocity waveforms and a low extent of the systemic shunt have a good extrauterine adaptation. A full clinical evaluation of the affected neonates at the end of the first week of live is now the best way to select the infants for intravascular embolization.

Modeling and implementing a database on drugs into a hospital intranet

Our objective was to develop a drug information service, implementing a database on drugs in our university hospitals information system. Thériaque is a database, maintained by a group of pharmacists and physicians, on all the drugs available in France. Before its implementation we modeled its content (chemical classes, active components, excipients, indications, contra-indications, side effects, and so on) according to an object-oriented method. Then we designed HTML pages whose appearance translates the structure of classes of objects of the model. Fields in pages are dynamically fulfilled by the results of queries to a relational database in which information on drugs is stored. This allowed a fast implementation and did not imply to port a client application on the thousands of workstations over the network. The interface provides end-users with an easy-to-use and natural way to access information related to drugs in an internet environment.

Demographic and familial characteristics of HTLV-1 infection among an isolated, highly endemic population of African origin in French Guiana

To determine the epidemiological characteristics of human T cell leukemia/lymphoma virus type I (HTLV-I) infection in the endemic village of Maripasoula, French Guiana, 1,614 persons (83.2% of the population) aged 2 to 91 years (mean age 21) were studied from November 1994 through April 1995. Plasma samples were screened by an HTLV-I ELISA and an IFA test (on MT2 cells), and positive samples were tested by an HTLV-I and -II type-specific Western blot. Overall seropositivity in the village was 6.7%, but HTLV-I infection was restricted to 3 of 6 ethnic groups, including the Noir-Marron (descendants of escaped African slaves, 8%), the Creoles (4.1%) and those of mixed Noir Marron/other ethnicity (3.6%). In the Noir-Marron population of 1,222 persons, including 606 men and 616 women and representing 76% of those tested, HTLV-I seroprevalence increased significantly with age in both sexes, reaching 40% in women older than 50 years. Univariate risk factors for HTLV-I seropositivity in women included older age, more pregnancies, more live births and a history of hospitalization. A cross-sectional analysis of sexual partners demonstrated an excess of discordant female HTLV-I+/male HTLV-I- couples, indicating preferential male-to-female sexual transmission. The demonstration of II HTLV-I-seropositive children aged less than 15 years, of whom 9 had a seropositive mother, suggested maternal-child HTLV-I transmission. Our results demonstrate a very high seroprevalence of HTLV-I in this South American population descended from African slaves, probably due to high rates of mother-to-child and sexual transmission within this rather isolated group.

Demographic and familial characteristics of HTLV-1 infection among an isolated, highly endemic population of African origin in French Guiana

To determine the epidemiological characteristics of human T cell leukemia/lymphoma virus type I (HTLV-I) infection in the endemic village of Maripasoula, French Guiana, 1,614 persons (83.2% of the population) aged 2 to 91 years (mean age 21) were studied from November 1994 through April 1995. Plasma samples were screened by an HTLV-I ELISA and an IFA test (on MT2 cells), and positive samples were tested by an HTLV-I and -II type-specific Western blot. Overall seropositivity in the village was 6.7%, but HTLV-I infection was restricted to 3 of 6 ethnic groups, including the Noir-Marron (descendants of escaped African slaves, 8%), the Creoles (4.1%) and those of mixed Noir Marron/other ethnicity (3.6%). In the Noir-Marron population of 1,222 persons, including 606 men and 616 women and representing 76% of those tested, HTLV-I seroprevalence increased significantly with age in both sexes, reaching 40% in women older than 50 years. Univariate risk factors for HTLV-I seropositivity in women included older age, more pregnancies, more live births and a history of hospitalization. A cross-sectional analysis of sexual partners demonstrated an excess of discordant female HTLV-I+/male HTLV-I- couples, indicating preferential male-to-female sexual transmission. The demonstration of II HTLV-I-seropositive children aged less than 15 years, of whom 9 had a seropositive mother, suggested maternal-child HTLV-I transmission. Our results demonstrate a very high seroprevalence of HTLV-I in this South American population descended from African slaves, probably due to high rates of mother-to-child and sexual transmission within this rather isolated group.

ARIANE: integration of information databases within a hospital intranet

Large information systems handle massive volume of data stored in heterogeneous sources. Each server has its own model of representation of concepts with regard to its aims. One of the main problems end-users encounter when accessing different servers is to match their own viewpoint on biomedical concepts with the various representations that are made in the databases servers. The aim of the project ARIANE is to provide end-users with easy-to-use and natural means to access and query heterogeneous information databases. The objectives of this research work consist in building a conceptual interface by means of the Internet technology inside an enterprise Intranet and to propose a method to realize it. This method is based on the knowledge sources provided by the Unified Medical Language System (UMLS) project of the US National Library of Medicine. Experiments concern queries to three different information servers: PubMed, a Medline server of the NLM; Thériaque, a French database on drugs implemented in the Hospital Intranet; and a Web site dedicated to Internet resources in gastroenterology and nutrition, located at the Faculty of Medicine of Nice (France). Accessing to each of these servers is different according to the kind of information delivered and according to the technology used to query it. Dealing with health care professional workstation, the authors introduced in the ARIANE project quality criteria in order to attempt a homogeneous and efficient way to build a query system able to be integrated in existing information systems and to integrate existing and new information sources.

[Extension of an acinar cell pancreatic carcinoma with cystic changes invading the Wirsung canal]

We report a case of acinar cell carcinoma of the pancreas with misleading cystic changes. A 32-year-old woman presented with symptoms suggesting acute pancreatitis on chronic pancreatitis. The abdominal computed tomography and the endoscopic retrograde pancreatography demonstrated hypertrophy of the pancreatic head associated with global dilatation of main pancreatic duct and secondary canals and a 5 cm communicating cyst. A intraductal papillary-mucinous tumor was suggested. Microscopic findings showed a poorly differentiated adenocarcinoma. Six months later, a liver metastasis was detected. The microscopic appearance was different, suggesting acinar cell carcinoma, confirmed by immunohistochemistry. Only two other cases of acinar cell carcinoma with cystic component have been reported in the literature.

[Neonatal hypoxemia due to misaligned pulmonary vessels with alveolar capillary dysplasia]

BACKGROUND

Refractory hypoxemia in the newborn requires a precise diagnostic investigation for optimal and fast management.

CASE REPORT

A full term newborn presented with refractory hypoxemia associated with radiologically clear lung fields and extrapulmonary shunt. Echocardiography ruled out a cardiac malformation. The persistence of hypoxemia despite treatment of the extrapulmonary shunt and the absence of parenchymatous pulmonary disease led to suspect misaligned lung vessels with alveolar capillary dysplasia. This diagnosis was confirmed by post mortem microscopic examination of the lung.

CONCLUSION

The diagnosis of misaligned lung vessels with alveolar capillary dysplasia can be suspected on clinical features. The disposition of pulmonary veins must be checked to recognize this disease in case of neonatal death with pulmonary hypertension.

Towards semantic integration within an existing medical information system

Talking about the problems of integration in medical information systems, the necessity to provide end users with a consistent and coherent view of patient's data, has been largely reported. In order to attempt this goal, systems need to perform semantic integration. We propose a pragmatic way to describe the semantics of the elements of a database, based on a bottom-up three steps process: 1. a back documentation of the elements of the system from their description contained in the data catalog of the database 2. a first semantic extension to transform a data catalog into a data dictionary 3. a second semantic extension to create a dictionary of the medical concepts from a data dictionary. This dictionary of concepts can be considered as the final result of "semantic integration". It contains a set of entities directly understandable by the end users. These entities are deduced or built from the elements collected and characterized in the data dictionary. This work reports the conceptual analysis and the implementation of such a data dictionary.

Towards interoperability of information sources within a hospital Intranet

Information is usually available in heterogeneous data format and various legacy sources. Interoperability appears to be a major approach for applications to access information. The project ARIANE is devoted to provide end-users with an easy to use and natural access to information databases. In this frame we defined actors able to operate the mediation between end-users and information servers: a "broker" which selects appropriate resources and "mediators" which access data suppliers. We have implemented a web-oriented stand-alone prototype accessing three types of information sources: a bibliographical server, a SQL database server and a hypertext server. Both broker and mediators exploit the Unified Medical Language System knowledge sources, especially the Information Sources Map which allows a way to identify information servers.

Review of biomedical knowledge and data representation with conceptual graphs

The basis of conceptual graphs theory is an ontology of types of concepts. Concepts issued from the ontology are interlinked by semantic relationships and constitute canonical conceptual graphs. Canonical graphs may be combined to derive new conceptual graphs by means of formation rules. This formalism allows to separate knowledge representation into a conceptual level and a domain-dependent level, and enables to share and reuse a representation. This paper presents conceptual graph applications to biomedical data and concept representation, classification systems, information retrieval, and natural language understanding and processing. A discussion on the unifying role conceptual graphs theory plays in the implementation of knowledge-based systems is also presented.

UMLS-based conceptual queries to biomedical information databases: an overview of the project ARIANE. Unified Medical Language System

OBJECTIVE

The aim of the project ARIANE is to model and implement seamless, natural, and easy-to-use interfaces with various kinds of heterogeneous biomedical information databases.

DESIGN

A conceptual model of some of the Unified Medical Language System (UMLS) knowledge sources has been developed to help end users to query information databases. A query is represented by a conceptual graph that translates the deep structure of an end-user's interest in a topic. A computational model exploits this conceptual model to build a query interactively represented as query graph. A query graph is then matched to the data graph built with data issued from each record of a database by means of a pattern-matching (projection) rule that applies to conceptual graphs.

RESULTS

Prototypes have been implemented to test the feasibility of the model with different kinds of information databases. Three cases are studied: 1) information in records is structured according to the UMLS knowledge sources; 2) information is able to be structured without error in the frame of the UMLS knowledge; 3) information cannot be structured. In each case the pattern-matching is processed by the projection rule according to the structure of information that has been implemented in the databases.

CONCLUSION

The conceptual graphs theory provides with a homogeneous and powerful formalism able to represent both concepts, instances of concepts in medical contexts, and associations by means of relationships, and to represent data at different levels of details. The conceptual-graphs formalism allows powerful capabilities to operate a semantic integration of information databases using the UMLS knowledge sources.

[Sarcomatoid variant of chromophobe renal cell carcinoma. Report of 2 cases]

In this paper, we report two cases of sarcomatoid carcinoma arising in chromophobe carcinoma. The sarcomatoid component appeared as white, shiny areas, occupying less than 10% of each tumor and containing numerous mitotic figures. Whereas both components expressed cytokeratin, only the carcinomatous cells were positive for epithelial membrane antigen and only the sarcomatoid cells were found to express vimentine. Sarcomatoid transformation in chromophobe cell carcinoma has been reported exceptionally. An aggressive behavior may be expected. The variable proportion of sarcomatoid component may lead to multiplication of the samples, especially when white, firm and shiny areas are detected on gross findings.

Role of the thermic effect of food in malnutrition of patients with chronic obstructive pulmonary disease

Malnutrition in patients with chronic obstructive pulmonary disease (COPD) is classically ascribed to an increased resting energy expenditure (REE) secondary to high cost of breathing. However, malnutrition correlates only weakly with the severity of respiratory dysfunction, which suggests other mechanisms. The aim of the present study was to determine the possible role of diet-induced thermogenesis (DIT). Therefore, we evaluated the relationship between DIT and nutritional status, in particular fat-free mass (FFM) estimated by bioelectrical impedance analysis in 26 patients with stable COPD (mean FEV1 +/- SEM = 36.5 +/- 3.8% of predicted). Ten patients were undernourished (weight < 90% of ideal body weight [IBW] and/or FFM < 69% of IBW), and 16 were normally nourished. Diet-induced thermogenesis was determined by comparing postprandial energy expenditure and REE, the latter being measured after an overnight fast and the former over 4 h after a mixed test meal of 0.4 times REE load. No statistical difference in DIT was found between undernourished and eutrophic patients. There was no relationship between DIT and nutritional or functional parameters, notably FFM. These results suggest that malnutrition is not a consequence of an increased DIT.

A UMLS-based method for integrating information databases into an Intranet

The Internet and the World Wide Web provide today end-users with capabilities to access universally to information in various and heterogeneous databases. The biomedical domain benefits from this new technology, specially for information retrieval by searching and browsing various sites. Nevertheless, end-users may be disoriented by specific ways to access information on different servers. In the framework of an Intranet design and development, we present a method for integrating information databases based on knowledge sources of the UMLS. The method provides designers of a Web site with facilities to implement an easy and homogeneous access to information. The pages are built dynamically and displayed according to a style sheet and their content stored in a database during the design phase. The database also describes the links between pages. Moreover, this organization provides administrators with powerful capabilities to manage Web sites.

Plasma concentrations and pharmacokinetics of idebenone and its metabolites following single and repeated doses in young patients with mitochondrial encephalomyopathy

OBJECTIVE

The pharmacokinetics and tolerance of idebenone after single or repeated doses have been studied in young patients with mitochondrial encephalomyopathy.

RESULTS

No significant adverse effects were noted. In 3 out of 7 patients idebenone induced overall stimulation and improvement in arousal. Plasma concentrations of idebenone and its main metabolites were determined and the pharmacokinetic parameters of idebenone after single and repeated doses were estimated. During the single dose study, the mean plasma concentrations of idebenone and its main metabolites and mean pharmacokinetic parameters were comparable to published results (Cmax = 452.2 ng.ml-1, tmax = 2.3 h, AUC = 26 micrograms. ml-1.h, t1/2 beta = 16.5 h). During the repeated doses study, no significant difference was found between mean residual plasma concentrations of idebenone on Day 2 (47 ng.ml-1) and Day 5 (70.6 ng.ml-1), and mean t1/2 beta of idebenone after the single and after repeated dose studies, i.e., there was no evidence of accumulation. Although idebenone did not appear to accumulate during this study, the coadministration of anticonvulsants, often prescribed during mitochondrial encephalomyopathy, can affect its pharmacokinetics.

[Histopathologic features of cytomegalovirus lymphadenitis in the "immunocompetent" patient. Report of 7 cases]

The authors report seven cases of cytomegalovirus lymphadenitis in apparently immunocompetent patients. One patient presented with an infectious mononucleosis-like illness. The main presentation of the others was isolated cervical lymphadenopathies. The lymph node pathology showed aspecific lymphoid hyperplasia, resembling the human immunodeficiency virus related lymphadenopathy, associated with diagnostic inclusion cells. Infected cells were confined to areas of monocytoid B cell hyperplasia in all cases whereas exceptionally observed in germinal centers. Because of their variable appearance, serial sectioning was frequently necessary to disclose their characteristic features. In all cases, immunohistochemistry using an anti-cytomegalovirus antibody was positive and revealed more infected cells than detected by morphology alone. Except for the endothelial cell, the nature of infected cells remained undetermined. An alteration of the antigenic expression as a consequence of cell infection might be responsible for immunohistochemistry failure in the cell characterization.

The project ARIANE: conceptual queries to information databases

As information databases we consider all the collections of data records indexed by key-words, stored and delivered by computer systems. In previous research works we demonstrated the interest to design a conceptual model, in the conceptual graphs formalism, and to implement a computational model for information retrieval in large information databases. These models are based on the UMLS knowledge sources. This paper reminds briefly these models and describes tests done in querying a patients database and a bibliographical database.

Clustering and clinical diversity of adult T-cell leukemia/lymphoma associated with HTLV-I in a remote black population of French Guiana

An epidemiological study was performed in French Guiana (population 115,000) to determine the prevalence and incidence of adult T-cell leukemia/lymphoma (ATL) associated with human T-cell leukemia/lymphoma virus type I (HTLV-I). From January 1990 to December 1993, all suspected cases of ATL were enrolled in this study, and their clinical, epidemiological and immunovirological features were analyzed. Out of the 19 suspected cases, 18 were considered as ATL associated with HTLV-I (8 acute forms, 8 lymphoma types and 2 smoldering cases). Before this study, only 2 ATL cases had been reported in French Guiana over a 10-year period. This demonstrates that the number of ATL cases is greatly under-estimated in most tropical HTLV-I endemic areas unless a specific disease search is performed. The mean age of the patients was 41 years. While HTLV-I antibodies were present in all cases, molecular studies demonstrated a clonal integration of HTLV-I in the tumoral cells in 7 cases out of the 9 tested. Fifteen patients died within a year of diagnosis. The crude incidence rate of ATL in French Guiana is around 3.5/100,000/year, a situation similar to that found in the Caribbean and in HTLV-I-endemic regions of Japan. However it reaches around 30/100,000/year (highest incidence ever described) in a small remote ethnic group of African origin (around 6200 inhabitants). Possible causes of ATL clustering in this ethnic group are presented.

Acts and knowledge management in the NUCLEUS hospital information system

NUCLEUS is a project completed in June 1995 in the frame of the European Community programme AIM (Advanced Informatics in Medicine). The main result of NUCLEUS is a prototype of an integrated patient dossier. Together with this patient dossier, facilities have been developed for its customisation by the various categories of end-users. A semantic model has been designed to guide and control the exploitation of data, and ensures the overall integrity of the information system.

Users conceptual views on medical information databases

As information databases we consider all the kinds of information repositories that are handled by computer systems. When querying very large information databases, the end-users are often faced with the problem to parse their questions efficiently into the query languages of the computer systems. Conceptual graphs were initially designed for natural language analysis and understanding. Due to their closeness to semantic networks, their expressiveness is powerful enough to be applied to knowledge representation and use by computer systems. This work demonstrates that conceptual graphs are a suitable means to model both the information in patient databases and the queries to these databases, and that operations on graphs can compute the pattern matching process needed to provide the answers. A prototype that exploits this model is presented. Experiments have been made with the material furnished by the Unified Medical Language System project (version 2, 1992) of the National Library of Medicine, USA.

The RICHE Reference Architecture

The RICHE Reference Architecture defines an open framework for health care information systems. Developed within the ESPRIT II programme, it is now the basis of several implementations in hospitals in Italy, Portugal, Ireland, France and the UK, and of follow-up initiatives such as EDITH (ESPRIT, no. 7508), NUCLEUS (AIM II, no. 2025) and REFERENCE (a French hospitals' project). This contribution describes the RICHE Reference Architecture in detail. Special concern is centred on the modulus that constitute the basic platform of RICHE, and on the methodology applied to design the interactions between them.

A computational model of information retrieval with UMLS

A high level representation of data would clarify the complex collection of medical concepts, terms and relationships derived from standard classifications that the Unified Medical Language System contains. A conceptual model is described which represents the data structure. A second objective of this conceptual model is to provide users with the capability to build queries to information databases as easily as possible on the basis of this data structure. The methods used to build this model are semantic networks and conceptual graphs. The object-oriented computational model which implements this conceptual model is detailed. It reuses part of the generic C++ classes of the National Institutes of Health library. New classes are added to this library to implement the needed functionalities.

A conceptual model for information retrieval with UMLS

Information retrieval in large information databases is a non-deterministic process which needs a sequence of search steps generally. One of the main problems to which the end-users are faced is to parse efficiently their questions into the query language that the computer systems allow. Conceptual graphs were initially designed for natural language analysis and understanding. Due to their closeness to semantic networks, their expressiveness is powerful enough to be applied to knowledge representation and use by computer systems. This work demonstrates that conceptual graphs are a suitable means to model the end-users querieson the basis of the thesaurus and the semantic network of the UMLS project.