Biomedical subjects

F Volot

Publications and source records attributed to F Volot.

28 records · Page 2Linked to original sources

PubMed1995

[Acetabular anteversion in congenital luxation of the hip].

MATERIAL AND METHOD: Acetabular anteversion angle (AAA) and orientation angle of the iliac bone (AOOI) determined by use of a CT scan were studied in CDH. 55 children with CDH were selected on hip arthrography for this study. Subluxated hips were excluded (i.e. opposite hip of a unilateral CDH is normal). 10 boys and 45 girls with a mean of age of 2 years 1 month (extremes from 1 to 4 years 3 months) were studied. CT scan was performed before any orthopaedic treatment in 3 cases of bilateral luxation and 14 cases of unilateral. In the other cases, time between the end of orthopaedic treatment and CT scan varied between 4 and 18 months. A group of 23 normal children, 10 boys and 13 girls, (mean age of 2 years 10 months) served as reference group. On the selected CT slide we measured AAA, AOOI, IAA and IAP (anterior acetabular index and posterior acetabular index as proposed by Guggenheim). RESULTS: We noted that the orientation of the iliac bone was variable in the two groups. This orientation angle could have higher or lower values. AAA: in bilateral luxation, this angle was higher (16 degrees +/- 5 degrees) than in reference group (13 degrees +/- 4 degrees), p < 0.005. In unilateral luxation there was no statistical difference (14 degrees +/- 4 degrees) with reference group, between normal and pathological side and when CT scan was performed before or after orthopaedic reduction. AOOI: there was no significant difference between bilateral, unilateral or reference group. Correlation analysis showed that AAA and AOOI moved in the same direction. IAA: in bilateral luxation this index was higher (p < 0.001); in unilateral luxation only right luxation showed an higher index (p = 0.002). IAP: no significant difference between the different groups. DISCUSSION: This study shows that there is any typical CT scan aspects of morphologic abnormality in CDH. The lesions of the anterior or posterior acetabular wedge are variable. The orientation of the iliac bone is also variable; we concluded that acetabular anteversion must be analysed depending on the morphologic aspects of the anterior and posterior extremities of the acetabulum and iliac bone orientation.

Acetabulum↗

PubMed1994

Intervertebral disk vacuum phenomenon secondary to vertebral collapse: prevalence and significance.

PURPOSE: To evaluate the prevalence of the intervertebral vacuum phenomenon in disks adjacent to vertebral collapses of various causes. MATERIALS AND METHODS: The authors retrospectively studied 310 consecutive patients who had at least one vertebral collapse. The vacuum phenomena were divided into collapse-related (ie, adjacent to a collapse) and degenerative (ie, not associated with a vertebral fracture) ones. Plain radiography was performed in all patients, and, in addition, conventional tomography, computed tomography, and/or magnetic resonance imaging was performed in 175 patients. RESULTS: Collapse-related vacuum phenomena were seen in 15% of patients with plain radiography and in 21% when all of the imaging modalities were considered. They occurred in association with all of the causes of collapse (ie, osteoporosis, multiple myeloma, metastasis, acute trauma, and vertebral osteomyelitis), although the prevalence was lower in association with metastasis or trauma (P = .008). The occurrence of collapse-related vacuum phenomenon was correlated with age (P = .001) and with the coexistence of degenerative disk-related vacuum phenomenon in the same patient (P = .0002). CONCLUSION: Occurrence of a vacuum cleft in disks adjacent to a vertebral collapse is common and appears as the second cause of vacuum phenomenon after degenerative disk disease.

Adult↗

PubMed1993

Analytical and statistical survey of early stages of open-angle glaucoma with low luminance visual field.

The purpose of this study was to show the early visual field signs in glaucoma using the 'Moniteur Ophtalmologique' at a background mesopic luminance of 0.3 apostilbs. Forty-five patients were selected, and 68 eyes with suspected early glaucoma were examined. Among the defects which were studied, we noticed a predominance of what we called pericaecal scotoma (PCS) and levelling. These two first signs appear as an alarm signal. To detect the early visual field signs of open-angle glaucoma developing, this study recommends the use of a background mesopic luminance of 0.3 apostilbs and observation for two uncommon visual field signs: PCS in evolution around the blind spot and a slight decrease in central mesopic sensitivity called levelling.

Adult↗

PubMed1993

Ocular growth in the fetus. 1. Comparative study of axial length and biometric parameters in the fetus.

The knowledge of ocular growth during fetal life, when compared with other fetal biometric parameters, could not only provide a better definition of malformation syndromes but could also give a better understanding of certain pathological processes in premature babies and in newborns. As the literature concerning prenatal ocular dimensions contains few data, the aim of this study was to measure the axial length of the globe (AL) in fetuses and compare this measurement with their gestational age, weight, height, head circumference (HC) and thoracic circumference (TC) in order to compile a reference table. In the present study, 76 globes from 38 fetuses (18-41 weeks gestational age) from the Department of Pathology (Timone University Hospital, Marseille) were examined. Ultrasonography A and B were used to measure the AL, and a pathological examination determined fetal weight, HC, TC and height. We were interested to find out which of the parameters studied would give the best correlation with ocular growth. Statistical analysis showed that HC remained the most discriminant factor and correlated best with ocular growth. We thus obtained an equation for ocular size according to HC that could serve as a basis for detecting pre- or postnatal ocular defects.

Anthropometry↗

PubMed1993

Ocular growth in the fetus. 2. Comparative study of the growth of the globe and the orbit and the parameters of fetal growth.

In a previous study, we showed that the growth of the eye during fetal development compared with the other parameters of the fetus was above all connected to the head circumference, which appeared to be the most discriminant measurement. In a second study, we measured the growth of the orbit of the fetus in order to compare it with the growth of the globe and the cranial circumference. Another 60 eyeballs of 30 fetuses of 18-41 weeks gestational age were examined. The corneal diameter (CD) of the cornea was a measurement added to those used in the method in the previous study, and orbital radiography was carried out: the parameters used were the same as in the previous study measured in relation to the CD, orbital diameter (OD) and the biparietal diameter (BPD). The aim of this study was to show the links between the variations in the measurements and to estimate them in relation to fetal growth. The results confirm those of the previous study, and this study also shows that, in estimating the head circumference, the OD and CD are the most accurate indicators. This study was also concerned with the BPD: the best correlation is obtained with the OD, which can be estimated accordingly from the BPD. Although the OD is not in an area studied by ultrasonography (highly dependent on the sectional plane), this study shows that it should perhaps be reconsidered in the prenatal diagnosis of orbital malformation. It would then be necessary to take into account not only the BPD but also the relationship between the OD and the BPD.

Anthropometry↗

PubMed1993

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.

Artificial Intelligence↗

PubMed1991

[Amikacin concentrations in lung and serum after single intratracheal administration in men].

This study was designed to assess the diffusion into lung tissue and systemic circulation of amikacin administered endotracheally. Eleven consecutive patients, suffering from lung carcinoma and scheduled for elective pneumonectomy or lobectomy, were included in the study. After induction of anaesthesia and before tracheal intubation, a single 500 mg amikacin dose was administered endotracheally through a catheter whose tip was located 5 cm below the vocal cords. Blood was then collected every 15 min for serum assays, until pulmonary resection had been carried out. Pulmonary concentrations were assessed in a healthy area. Measurements were carried out in duplicate using fluorescence polarizing immunoassay and microbiological methods. Serum peak concentrations were found 105 min after administration (7.97 +/- 5.62 micrograms.ml-1). Six and 12 h after administration, serum concentrations were 3.19 +/- 1.87 and 1.20 +/- 0.67 micrograms.ml-1 respectively. Mean lung concentrations were 1.85 +/- 2.12 micrograms.g-1, with a corresponding serum level of 7.22 +/- 4.36 micrograms.ml-1. However, endotracheal instillation of amikacin provided serum concentrations which, were not high enough for treatment of gram negative pneumonia. Lung concentrations are lower than both serum levels and MIC90 for gram negative bacilli. Moreover, there was a major heterogeneity in serum and lung levels, which seemed to be unpredictable. This was probably due to heterogenous tracheal, bronchial and alveolar absorption. The results obtained in this study with a single dose administration should be reassessed in the light of data obtained with long-term amikacin administration.

Administration, Inhalation↗

PubMed1991

[Treatment of cardiogenic shock with exclusion of inotropic drugs].

Cardiogenic shock comprises peripheral hypoperfusion and pulmonary vascular overload. The goals of therapy are to reduce pulmonary congestion by lowering pulmonary capillary wedge pressure and to increase cardiac index. Volume loading is the first step of treatment. It helps to place the patient on the Franck-Starling relationship. This challenge studies the effects of an increased preload on stroke volume. It has to be done even in case of major heart failure. The main effect of venous vasodilators is to decrease myocardial oxygen consumption. Arteriolar vasodilators also decrease left ventricular end systolic volume. Fluid overload may be treated by diuretics or by extra renal devices: peritoneal dialysis or hemofiltration. Intractable cardiogenic shock may respond to cardiac assist devices (intra aortic balloon pump, pump assistance) as a bridge to surgery.

Counterpulsation↗

PubMed1990

[Comparison of enoximone versus tobutamine in the treatment of low cardiac output after cardiac surgery].

Enoximone, a new cardiotonic agent not related to glycosides or catecholamines, has been suggested for treatment of low cardiac output syndromes occurring after cardiopulmonary bypass (CPB). The aim of the present study was to compare enoximone with dobutamine in the management of such cases. Twenty consecutive patients who had undergone cardiac surgery with CPB and who had a cardiac index (CI) less than 2.5 l.min-1.m-2, pulmonary capillary wedge pressure greater than 12 mmHg, and no renal failure, were randomly assigned to receive either enoximone (group E, n = 10) or dobutamine (group D, n = 10). The following parameters were monitored at baseline, 15, 30, 60, 90 min, 2, 6, 10 and 14 h: arterial, central venous, pulmonary arterial and capillary wedge pressures (PCWP), cardiac index (CI), stroke volume index (SVI), stroke work index (SWI), systemic (SVR) and pulmonary vascular resistances, as well as heart rate-pressure product (HRPP). Patients in group E were given a bolus of 0.5-1 mg.kg-1 enoximone over a 20 min period, followed by a continuous infusion of 2-20 micrograms.kg-1.min-1, depending on clinical response. In group D, patients were given 2.5 to 15 micrograms.kg-1.min-1 dobutamine according to clinical response. No other inotropic drug was used during the study period. The aim was to obtain an increase in CI greater than or equal to 30% at the end of the first hour of treatment. Excessive systemic hypotension with low SVR was treated with volume loading.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

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.

Databases as Topic↗