Representing clinical narratives using conceptual graphs.

The analysis of medical narratives and the generation of natural language expressions are strongly dependent on the existence of an adequate representation language. Such a language has to be expressive enough in order to handle the complexity of human reasoning in the domain. Sowa's Conceptual Graphs (CG) are an answer, and this paper presents a multilingual implementation, using French, English and German. Current developments demonstrate the feasibility of an approach to natural Language Understanding where semantic aspects are dominant, in contrast to syntax driven methods. The basic idea is to aggregate blocks of words according to semantic compatibility rules, following a method called Proximity Processing. The CG representation is gradually built, starting from single words in a semantic lexicon, to finally give a complete representation of the sentence under the form of a single CG. The process is dependent on specific rules of the medical domain, and for this reason is largely controlled by the declarative knowledge of the medical Linguistic Knowledge Base.

Multilingual natural language generation as part of a medical terminology server.

Re-usable and sharable, and therefore language-independent concept models are of increasing importance in the medical domain. The GALEN project (Generalized Architecture for Languages Encyclopedias and Nomenclatures in Medicine) aims at developing language-independent concept representation systems as the foundations for the next generation of multilingual coding systems. For use within clinical applications, the content of the model has to be mapped to natural language. A so-called Multilingual Information Module (MM) establishes the link between the language-independent concept model and different natural languages. This text generation software must be versatile enough to cope at the same time with different languages and with different parts of a compositional model. It has to meet, on the one hand, the properties of the language as used in the medical domain and, on the other hand, the specific characteristics of the underlying model and its representation formalism. We propose a semantic-oriented approach to natural language generation that is based on linguistic annotations to a concept model. This approach is realized as an integral part of a Terminology Server, built around the concept model and offering different terminological services for clinical applications.

Toward a medical linguistic knowledge base.

This paper presents the design of a Medical Linguistic Knowledge Base (MLKB). This MLKB is intended to be the multilingual recipient for all the declarative knowledge about languages. It includes words, their syntax and their conceptual representation, typology of concepts of the domain, rules for semantic analysis and conceptual schemata. For that purpose, Sowa's conceptual graphs are considered as an adequate knowledge representation. The MLKB will be an enormous body of information, and the difficulty to feed it and to validate it appears immediately. Therefore, it is necessary to start an international initiative to merge efforts from different groups.

Constructing clinical applications: the GALEN approach.

A common problem for developers of clinical applications is coping with the diversity of medical language. Medical language as it is used all over the world varies widely, while the referents for these words stay essentially the same. Software developers must reconcile this diversity with the practical necessity of producing applications that are usable in a variety of hospitals, while ensuring that information can be shared between applications. Existing approaches center around coding and classification schemes, but these approaches must be supplemented by a range of sophisticated terminological services in order for the language barriers to be overcome. To address this, the GALEN project is developing an application called the Terminology Server to provide such a range of terminological services (e.g., conceptual and multilingual services). The software is built upon a re-usable core model of medical terminology. This paper reports on the development of a clinical application called the SCUI (Structured Clinical User Interface) which draws on these GALEN technologies and illustrates an innovative approach to the construction of future clinical applications. The SCUI was specifically developed and tested in the context of infectious diseases to satisfy the demands made by the medical intensive care unit on the Geneva Hospital's microbiology laboratory.

Natural language processing of medical texts within the HELIOS environment.

A large number of hospital applications are potentially interested in natural language processing since they currently heavily depend on an efficient use of a huge amount of textual information. The need for systems that are able to accept multiple European languages is of paramount interest, as language barriers can be a strong impediment for large-scale communication in Europe, in particular regarding telemedicine. In the context of the AIM project HELIOS, the Natural Language Processing (NLP) component offers a large variety of medical services according to natural language free input. It allows the multilingual analysis of medical texts (currently in English, French and German) and the storage of the meaning of these texts under a deep knowledge representation that can be queried whenever it is needed. In addition, it provides facilities to handle knowledge source embedded into the conceptual typologies and into the dictionaries. This article aims at describing all these functionalities and their integration into the environment of the HELIOS project.

Pharmacokinetics of 3,5,3'-triiodothyroacetic acid and its effects on serum TSH levels.

3,5,3'-triiodothyroacetic acid is an effective inhibitor of TSH secretion in central hyperthyroidism. Serum, 3,5,3'-triiodothyroacetic acid was measured with an RIA preceded by immunoprecipitation. An anti-3,5,3'-triiodothyroacetic acid antibody was obtained in rabbits, using 3,5,3'-triiodothyroacetic acid coupled to hemocyanin and diazotized benzidine as antigen (cross-reactivity with T4, T3, tetraiodothyroacetic acid was 0.2, 1.1, and 5%, respectively). Endogenous 3,5,3'-triiodothyroacetic acid levels could not be detected in 14 euthyroid, 10 hypothyroid and 10 hyperthyroid sera (detection limit 0.055 nmol/l). Kinetic studies were performed in 6 healthy male subjects who received an oral and an iv dose of 1050 micrograms of 3,5,3'-triiodothyroacetic acid. The serum measurements were analysed according to a non-compartmental method. The half-life of 3,5,3'-triiodothyroacetic acid was 6 h 22 min +/- 29 min, the volume of distribution was 114 +/- 9 1/70 kg, and the plasma clearance rate was 298 +/- 141.(70 kg)-1.day-1. Highest 3,5,3'-triiodothyroacetic acid levels were measured after 40 min (for T3 2-3 h) and its absorption was 67 +/- 6%. The nadir of the mean TSH levels was 0.72 +/- 0.09 mU/l 6 h after 3,5,3'-triiodothyroacetic acid administration. However, the time course of serum TSH response did not differ from that obtained after administration of 37.5 micrograms T3. The dose-response effect for TSH was studied using oral doses of 350, 700, 1400 and 2800 micrograms 3,5,3'-triiodothyroacetic acid. TSH was measured 9 h after 3,5,3'-triiodothyroacetic acid administration at 17.00 h, and compared with control serum TSH levels obtained at 08.00 h (1.53 +/- 0.11) and at 17.00 h the day before the test (1.87 +/- 0.11). They were 1.05 +/- 0.15 (N = 9, mean +/- SEM), 0.83 +/- 0.08 (N = 24), 0.66 +/- 0.06 (N = 24), and 0.43 +/- 0.02 mU/l (N = 6), respectively. In conclusion, TSH inhibition by 3,5,3'-triiodothyroacetic acid is similar to T3, with a potency ratio of 1 to 18.

Left ventricular function during propofol and fentanyl anesthesia in patients with coronary artery disease: assessment with a radionuclide approach.

Using gated radionuclide ventriculography and invasive cardiac monitoring, the effects of propofol alone and in combination with fentanyl on left ventricular (LV) volumes and function were investigated in 10 ASA III, unpremedicated patients (51-75 years) with coronary artery disease (NYHA II-III). Anesthesia was induced with propofol (2 mg/kg) followed by an infusion (100 micrograms.kg-1.min-1). Vecuronium (0.05 mg/kg) was administered and ventilation (FIO2, 1.0) was manually controlled via a face mask (FECO2, 4-5%). Data acquisitions were serially obtained over 15 minutes after the bolus IV injection of propofol and 5 minutes after the injection of fentanyl (5 micrograms/kg). Propofol induced a rapid decrease (15%) in mean arterial pressure (MAP) exclusively related to a decrease in cardiac index (CI), without reduction in indexed systemic vascular resistances (SVRI). Despite the decrease in MAP, heart rate did not change. The decrease in CI was associated with a lower preload. After the addition of fentanyl, MAP decreased significantly (35%) below the last set of propofol measurements. The decrease in MAP was associated with a reduction in CI and SVRI. Fentanyl was also associated with a significant decrease in heart rate (16%) resulting in a decrease in CI, whereas stroke index and end diastolic volume did not change. Neither global ejection fraction (EF) nor end systolic volume changed significantly at any time, nor were there changes in the ECG or in regional ejection fractions (REF). The absence of changes in REF was consistent with lack of wall motion abnormalities of the left ventricle. Propofol alone and in combination with fentanyl does not alter LV performance in patients with good LV function.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative study of first-line ceftriaxone and amikacin in the treatment of severe urinary tract infections in the adult]. / Etude comparative de la ceftriaxone et de l'amikacine en première intention dans le traitement des infections urinaires sévères de l'adulte.

After randomization in 2 groups of 20, 40 adult patients with a severe urinary tract infection (post-urologic surgery, pyelonephritis, prostatitis, neurologic bladder dysfunction, Foley catheter) received as first-line therapy, ceftriaxone (CFX) 1 g/24 h im or amikacin (AMK) 500 mg/24 h im during at least 5 days. The clinical and bacteriological efficiency and the tolerance of the 2 agents are equivalent. In the 2 groups, all patients but one are clinically cured. In the CFX group, 2 patients had resistant organisms (E. cloacae, strepto D) to first-line antibiotic. 48 hours after the beginning and at the end of the treatment, the percentage of urine sterilization was respectively 65 and 88 in the CFX group and 50 in the AMK group. In both groups, 60% of the patients showed negative first-month follow-up urine specimen. Underlying urinary tract pathology contributed to persistence of the original infecting organism, reinfection or relapse; the responsible isolate remained sensitive to the first-line antibiotic.

Effects of rifampicin on the peripheral turnover kinetics of thyroid hormones in mice and in men.

The induction of mixed function hepatic oxygenases by rifampicin is known to increase the metabolic clearance rate (MCR) of T4. By performing T3 and rT3 kinetics we have shown that rifampicin also increases the MCR of T3 and rT3. Using the fall of serum T4 during TSH suppression as an indirect marker of the production rate (PR) of T4, we have demonstrated that there was no major change in monodeiodination nor any shift to either 5'- or 5-monodeiodination. Rifampicin stimulates in mice the mixed function hepatic oxygenases. However, we were unable to increase hepatic deiodinase activity (deiodinase type I) in this species. It is therefore possible that the increased MCR of T4 in man is not mediated by an increased conversion rate either. As mixed function hepatic oxygenases are known to increase hepatic conjugation it is suggested that rifampicin increases the biliary excretion of iodothyronine conjugates.

[Effect of propofol on left ventricular function in the coronary patient. Combined isotopic and hemodynamic studies]. / Impact du propofol sur la fonction ventriculaire gauche du coronarien. Etudes isotopique et hémodynamique couplées.

The present study investigated the effects of propofol (P) as sole anaesthetic agent of left ventricular (LV) function using gated radionuclide ventriculography (RNV) in unpremedicated patients with chronic coronary arterial disease (CAD). After informed consent, seven ASA 111 patients (51-74 yr) undergoing major urologic surgery took part in this study. All patients suffered from documented angina pectoris secondary to CAD. None gave a history of congestive heart failure or valvular heart disease. No patients were premedicated, but all received their chronic medications (nifedipine and isosorbide) up to and including the morning of surgery. The study was performed in the Nuclear Medicine Laboratory just before surgery. Heart rate (HR) was obtained from standard limb lead II of the ECG. A 7.5 F thermodilution Swan-Ganz catheter and a radial artery cannula were inserted under local anaesthesia. All patients were studied by RNV using red blood cells (RBC) labelled in vivo with 99m-technetium (Tc). A first RBC-Tc preparation containing 2-3 mCi f Tc was counted 10 cm from a gamma-camera. A first-pass study was carried out in the left anterior oblique position following the bolus i.v. injection of the source, allowing the evaluation of the isotopic dilution cardiac output (COiso) and the attenuation factor (F). Then, a second RBC-Tc preparation containing 20-25 mCi of Tc was injected intravenously. At equilibrium, 16 ECG-synchronized frames were acquired by computer for processing. Mean end-diastolic (ED) and end-systolic (ES) counts, left ventricular-end diastolic and systolic areas and ejection fraction (EF) were calculated every 1.5 min.(ABSTRACT TRUNCATED AT 250 WORDS)

[Curarization of the myasthenia patient by atracurium]. / Curarisation du patient myasthénique par l'atracurium. Atracurium in the myasthenic patient.

The use of atracurium, a new intermediate duration of action non depolarizing muscle relaxant, is described in a myasthenic patient undergoing abdominal surgery. The effective dose to 95% twitch suppression is 0.15 mg.kg-1. Following the first dose, the time from maximum twitch depression to 25% recovery is 32 min, and 33 min following the second dose. The recovery index (25-75% recovery time) and the 5-90% recovery time are respectively 33 and 83 min. The train-of-four ratio is greater than 0.7 within 90 min after the reinjection. The significance of the behaviour of atracurium is discussed. In reduced dosage and with careful neuromuscular monitoring, atracurium appears to be a reasonable and safe choice of myasthenic patients to provide surgical relaxation.

[Congestive cardiomyopathy and pyruvate elevation in a case of Charcot-Marie-Tooth disease]. / Cardiomyopathie congestive et augmentation du pyruvate dans un cas de maladie de Charcot-Marie-Tooth.

The case is reported of a patient with Charcot-Marie-Tooth disease and congestive cardiomyopathy. This is an exceptional association and suggests there could be transitional forms between Charcot-Marie-Tooth disease and Friedreich ataxia, which is frequently associated with hypertrophic cardiomyopathy. A disorder of pyruvate metabolism observed in our patient could explain both the neurologic and cardiac symptoms.

[Spinal anesthesia with bupivacaine in lower urologic surgery. Our experience apropos of 500 cases]. / La rachianesthésie à la bupivacaäine en chirurgie urologique basse. Notre expérience à propos de 500 cas.

Rachianesthesia was used for 500 lower urinary tract operations, including 50 repeat procedures, the anesthetic employed being bupivacaine. Patients were frequently hypertensive and presented cardiopathies, usually ischemic in origin. The surgical procedure generally involved transurethral prostate resection for adenoma or carcinoma, or endoscopic resection of a bladder tumor, and all patients received preventive heparin therapy using Kakkar's method. Induction of anesthesia occurs between 30 seconds and one minute after completing the injection a procedure lasting 2 to 5 minutes. Full anesthesia is obtained after 2 to 3 minutes, and is maintained during the mean operation period of 69 +/- 32 minutes by regular intraspinal injections of anesthetic. Results were perfect in 425 cases, 48 patients required additional sedatives, 23 a potent analgesic and 4 a general anesthetic after an operating time extending beyond 100 minutes heart rate remained fairly regular while diminishing slightly in frequency (an average of 4 beats/min). The fall in blood pressure was globally moderate (296 patients) and was unaltered in 204 cases. Hemodynamic modifications lasted for 3 à 4 minutes only and were corrected by appropriate therapy. Postoperative complications were mainly of the headache type (26 cases: 5%), but three patients developed angina from a coronary ischemic accident. Myocardial infarction was not observed, and no particularly incidents were reported in the 32 patients requiring repeat rachianesthesia. The simple execution and efficacy of this mode of anesthesia is emphasized, an additional need for general anesthesia being a rare event. The compound is well tolerated, hemodynamic modifications are moderate and neurological sequelae lacking. Rachianesthesia with bupivacaine appears to be among the methods of choice for lower urinary tract surgery.