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Biomedical subjects

M Joubert

Publications and source records attributed to M Joubert.

At least 73 records · Page 4Linked to original sources

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.

Databases, Bibliographic↗

[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.

Adult↗

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.

Adult↗

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.

Computer Communication Networks↗

Acts and knowledge management in an open hospital information system.

This communication presents the management of a customizable patient medical dossier as implemented in the NUCLEUS project. After a brief reminder of the NUCLEUS hospital information system features, we discuss the two main innovative concepts underlying the intelligent management of the integrated patient dossier: acts management and knowledge management. The functionalities related to patient dossier are then introduced.

Artificial Intelligence↗

A conceptual graphs modeling of UMLS components.

The Unified Medical Language System (UMLS) of the U.S. National Library of Medicine is a complex collection of terms, concepts, and relationships derived from standard classifications. Potential applications would benefit from a high level representation of its components. This paper proposes a conceptual representation of both the Metathesaurus and the Semantic Network of the UMLS based on conceptual graphs. It shows that the addition of a dictionary of concepts to the UMLS knowledge base allows the capability to exploit it pertinently. This dictionary defines more precisely the core concepts and adds constraints on their use. Constraints are dedicated to guide an "intelligent" browsing of the UMLS knowledge sources.

Dictionaries as Topic↗

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.

Abstracting and Indexing↗

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.

Information Storage and Retrieval↗

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.

Information Storage and Retrieval↗

Effect of two-week treatment with enprostil (35 micrograms twice a day) on 24-hour serum gastrin levels.

After a meal, a single dose of enprostil, a synthetic dehydroprostaglandin E2, inhibits gastrin level in both normal subjects and patients with duodenal ulcer, whereas H2 blockers exaggerate the postprandial gastrin response. However, the effect of prolonged treatment with enprostil on the gastrin profile is unknown. The aim of this study was to compare serum gastrin levels over a 24-hr period before (day 0) and on the last day (day 14) of a two-week course of enprostil (35 micrograms twice a day). Nine healthy volunteers (four women and five men), ages 29 +/- 5 years (range 23-39) were studied twice during a 24-hr period. Serum gastrin was measured at 30-min intervals during the day and at 2-hr intervals during the night. Enprostil (35 micrograms) was taken after basal gastrin serum measurement at 8:00 AM and PM. Standardized meals were ingested at 8:30 AM, 12:30 PM, and 8:30 PM. The postprandial integrated serum gastrin response was calculated after the three meals (4-hr period). Fasting serum gastrin levels were similar for the two periods. Integrated postprandial gastrin response was significantly inhibited after breakfast and dinner (P less than 0.001). Average results are expressed as mean +/- SEM (pmol/min/liter). During the night, gastrin levels were significantly decreased by enprostil. After 14 days, the inhibition of gastric acid secretion, which induces an increase of gastrin release with other antisecretory drugs, remained counterbalanced by the antigastrin properties of enprostil.

Adult↗

The effect of enprostil on duodeno-jejunal motility in man.

Motor changes could be involved in the pathogenesis of diarrhoea that complicates the treatment of ulcer disease by prostaglandins. Our aim was to assess the effect of enprostil, a synthetic analogue of PGE2, on duodeno-jejunal motility. During this randomized double-blind crossover study, two manometric recordings, each lasting 20 h (12.00-08.00 hours), were carried out during dosing with 35 micrograms enprostil b.d. or placebo (eight volunteers: part 1), or during dosing with 35 or 70 micrograms enprostil b.d. (nine volunteers: part 2). Subjects were only allowed a standard dinner at 18.00 hours. During fasting, in part 1, the number of phase 3 activity patterns (PIIIs) was higher with enprostil than with placebo (P less than 0.01), without any difference in their characteristics; the overall duration of phase 1 activity was longer with enprostil than with placebo (P less than 0.01). In part 2, during fasting the number and characteristics of the PIIIs were not different, but there was a dose-related increase in PI, and decrease in PII activity. Fed motor patterns did not differ between the two doses of enprostil.

Adult↗

Protective effect of low dose of enprostil against gastric blood loss induced by aspirin in man.

This study tested the efficacy of enprostil given both at potent antisecretory (35 micrograms twice daily) and weak antisecretory (7 micrograms twice daily) doses in preventing aspirin-induced gastric blood loss measured chemically in gastric washings in 10 volunteers. Aspirin (500 mg four times a day) increased gastric blood loss compared with placebo (p less than 0.001). When enprostil was given in addition to aspirin, gastric blood loss was not significantly different from basal value. The pH of gastric washings was significantly increased by the large but not by the low dose of enprostil compared with placebo. The two doses of enprostil were equally efficacious, suggesting a mucosal protective effect of enprostil independent of acid inhibition.

Adult↗

[Efficacy and tolerability of enprostil in the treatment of duodenal ulcer. Comparison with cimetidine].

Enprostil, a synthetic PGE2, has been shown to have an inhibitory effect on gastric acid secretion, a mucoprotective effect and a postprandial lowering effect on gastrin. A double blind randomized study was performed in 80 patients, in order to evaluate the efficacy and safety enprostil (35 mu b.i.d) as compared to cimetidine (400 mg b.i.d) in duodenal ulcer. Healing rates after two, four and six weeks of treatment, as based on endoscopic evaluation, were 35, 72 and 83 p. 100 for enprostil and 45, 73 and 83 p. 100 for cimetidine, respectively. There were no significant differences between treatment groups. The time to relief of nighttime and daytime ulcer pain and antacid consumption were similar in the two groups. The patient's overall subjective assessment was better in the cimetidine group, but this was not confirmed by physicians' opinions. Diarrhea was observed in 7 p. 100 of patients treated by enprostil compared with 5 p. 100 for patients treated by cimetidine. One enprostil treated patient withdrew from the trial prematurely because of abdominal pain. This study demonstrates the efficacy and safety of enprostil in the treatment of active duodenal ulcer at the dosage of 35 micrograms twice daily.

Adult↗

Titrated extract of Centella asiatica (TECA) in the treatment of venous insufficiency of the lower limbs.

Ninety-four patients suffering from venous insufficiency of the lower limbs participated in a multicenter, double-blind versus placebo study. After randomization, they were allotted for a treatment period of two months to one of three groups: TECA 120 mg/day, TECA 60 mg/day, or placebo. A significant difference (p less than 0.05) in favor of TECA was shown for the symptoms of heaviness in the lower limbs and edema, as well as for the overall evaluation by the patient. The venous distensibility measured by a mercury strain gauge plethysmograph at three occlusion pressures was improved for the TECA groups but aggravated for the placebo group.

Adult↗

[Effects of enprostil on changes in the gastric transepithelial potential differential induced by aspirin].

Enprostil (E), is a semisynthetic E2 prostaglandin with wide-range antisecretory properties. Administered orally E reduced mucosal injury in rats exposed to NSAID and gastric acid. The aim of the present study was to analyze the cytoprotective effect of 7 micrograms of E on the aspirin-induced (500 mg) decrease in gastric transepithelial difference of potential (DP) in a) five healthy volunteers and b) five patients with epigastric heartburn, normal endoscopy and a low gastric DP (mucosal barrier weakness). Aspirin-induced decrease of gastric DP was measured during two four hour periods separated by an interval of two days: a) during a one hour basal period and after three hours after 7 micrograms of E, and b) during a second basal period and one hour after aspirin, E, and then aspirin again. The following parameters were analyzed: maximal drop of DP DP Max (mV), area under the curve of DP drop, AUC (mV.min), and time to return to basal values, TRB (min). In the control group, when E was administered after aspirin, the decrease in DP Max (11.4 +/- 2.3 vs 6.6 +/- 2.1) and in AUC (68 +/- 22 vs 35 +/- 11) was significant (p less than 0.05) as compared with values obtained after aspirin alone. In the patient group, E produced a significant decrease in aspirin-induced DP Max (11.8 +/- 1.9 vs 6.8 +/- 2.4) (p less than 0.003) and in AUC (117 +/- vs 48 less than 22) (p less than 0.006) as well as in TRB (52 +/- 2 vs 37 +/- 10) (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗