Deep brain activities can be detected with magnetoencephalography.

The hippocampus and amygdala are key brain structures of the medial temporal lobe, involved in cognitive and emotional processes as well as pathological states such as epilepsy. Despite their importance, it is still unclear whether their  neural activity can be recorded non-invasively. Here, using simultaneous intracerebral and magnetoencephalography (MEG) recordings in patients with focal drug-resistant epilepsy, we demonstrate a direct contribution of amygdala and hippocampal activity to surface MEG recordings. In particular, a method of blind source separation, independent component analysis, enabled activity arising from large neocortical networks to be disentangled from that of deeper structures, whose amplitude at the surface was small but significant. This finding is highly relevant for our understanding of hippocampal and amygdala brain activity as it implies that their activity could potentially be measured non-invasively.

[Applying social network analysis to the health system]. / L'analyse des réseaux sociaux appliquée au système de santé.

BACKGROUND: Social network analysis is a method for describing and contextualising the structural relationships amongst social entities. The aim of this study was to assess the relationships between hospitals through the use of an example of a hospital that takes care of myocardial infarction in the region of Provence Alpes Côte d'Azur (PACA). METHOD: This retrospective study included all patients hospitalised for acute coronary syndrome in the PACA region between January and June 2000. The description analysis consisted of making a graph describing the transfer of patients between hospitals to calculate indicators for the centrality of the hospital and its prestige. The graph was also used to determine and measure the sub-group cohesion (cliques) and the density of the hospital network. RESULTS: A total of 2049 patients suffering from myocardial infarction were admitted to 78 hospitals during the study period. There were 867 transfers from one hospital to another. 51 cliques were highlighted; 29 hospitals do not belong to a clique. Among the 49 hospitals who do belong to sub-groups, 50% are linked to two cliques. Eight hospitals belong to more than 8 sub-groups, and the maximum number of sub-groups to which a hospital is linked is 12. The density of the hospital network is 0.12. CONCLUSIONS: Social network analysis is a field of research open and adaptable to the public health scene. This method could be applied to the evaluation of health and hospital administration and management networks.

Category-specific visual agnosia: lesion to semantic memory versus extra-lesional variables in a case study and a connectionist model.

There is a current debate on the causes of category-specific agnosia. The aim of this study was to examine the effects of lesional and extra-lesional variables on object recognition. Extra-lesional variables, such as visual complexity or familiarity, are factors that influence recognition. Using a connectionist model based on study, we provide evidence that extra-lesional variables can yield dissociations in the recognition rate of different categories. Furthermore, it is shown that lesional and extra-lesional variables can interact (p < .01) when both are simultaneously modeled. Category-specific agnosia might thus result from complex interactions.

Validation of a pain evaluation scale for patients with severe cerebral palsy.

Polyhandicapped children are extremely limited by severe mental retardation, motor deficiency, perception disability and expression troubles. So pain is very difficult to assess in these patients. We have developed a specific scale for rapid evaluation of pain based on the observation of their behaviour. A first questionnaire listing 22 items was elaborated by physicians and nurses on the basis of their clinical experience. The first part of our study was designed to select the most pertinent items in order to define a final scale for simple and reliable everyday use. The second part of our study was designed to demonstrate the construct validity and the psychometric qualities and to determine the threshold of decision of the 10-item final scale. This tool seems to be sensitive and reliable enough to assess pain in severely cerebrally palsied children and young adults.

Holodiastolic reversal flow in the common carotid: another indicator of the severity of aortic regurgitation.

Aortic regurgitation (AR) causes an increased diastolic reverse flow at various levels of aorta and its branching vessels. A prospective study was designed to evaluate the feasibility and accuracy of duplex sonography of the common carotid artery (CCA) in patients with various degrees of AR quantified by cardiac angiography. Twenty-four patients, with pure angiographic AR, of mean age 63.5 + 2.5-year old were included. Holodiastolic reverse flow (HRF) was recorded in all seven patients with severe angiographic AR (five with grade III and two with grade IV) and in none of the seventeen patients (eight with grade I and nine with grade II) with mild angiographic AR (p < 0.001). Furthermore, HRF was recorded both in the CCA and in the aorta, where it represents another criterion of severe AR, of six patients with severe angiographic AR and was absent in the eleven patients with grade I or II AR (p < 0.001). Demonstration of HRF in the CCA may be a very helpful criterion in distinguishing patients with severe AR.

[Hormone replacement therapy in menopause and colorectal disease]. / Traitement hormonal de la ménopause et pathologies colorectales.

Colorectal disease is frequent. Accumulating evidence indicates that postmenopausal hormone replacement therapy may reduce the risk of this pathology in women. Through MEDLINE computer searches, we identified English-language articles with quantitative data on the relation of postmenopausal hormone replacement therapy to colorectal cancers and adenoma. Twenty-four studies about colorectal cancer and five studies about colorectal adenoma were reviewed. Epidemiological data suggest a 20 to 30% reduced risk of colorectal cancer and adenoma among women taking postmenopausal hormones. There is biological evidence to support this association.

Diurnal variations in keratometry and refraction with intracorneal ring segments.

PURPOSE: To study refraction variations during the day in eyes with intrastromal corneal ring segments (ICRS) to correct low myopia. SETTING: Monticelli Clinic, Marseille, France. METHODS: Thirteen eyes with ICRS were included in the study; the ICRS was explanted from 3 eyes because of undercorrection. The minimum follow-up in all eyes was 1 year. The same observer measured refraction and keratometry at 9:00 AM, 1:00 PM, and 7:00 PM with the same autokeratorefractometer. To validate the analysis method, these eyes were compared with a group of emmetropic control eyes that had not had surgery and with a group of eyes that had photorefractive keratectomy for a similar degree of myopia. All measurements were done under the same conditions. RESULTS: After 1 year, the ICRS eyes showed a tendency toward an evening myopic shift. This was confirmed by the objective keratometry study, which showed variations closely correlated with the myopia observed. These phenomena were not observed in the other groups. CONCLUSION: The ICRS had satisfactory predictability in eyes with up to -3.50 diopters of myopia. However, the evening myopic shift appeared similar to that observed after radial keratotomy.

[Diurnal variations of refraction and keratometry after intracorneal rings]. / Variations diurnes de la réfraction et de la kératométrie observées après anneaux intracornéens.

UNLABELLED: Within a European evaluation, we participated in the study of ICRS on low myopia. During the period of observation, subjective refraction variations in the day were underlined. This phenomenon remains to be specified. MATERIAL AND METHODS: Thirteen eyes were included in the study, 3 were explanted because of under-correction. The minimum follow-up is one year for all eyes. The same observer measured refraction and keratometry in all eyes on the same day at 9:00 am, 1:00 p.m. and 7:00 p.m., with the same automatic autokeratorefractometer. To validate the analysis method, these patients were compared with a group of emmetropic control eyes never operated on and with a group of eyes operated on with a PRK for similar myopia. All measurements were done under the same conditions. RESULTS: After one year, a tendency to evening myopisation was noticed in ICRS eyes and confirmed by the objective keratometry study showing variations closely correlated with the myopia observed. These phenomena were not observed in the two other groups. DISCUSSION: The examination technique was validated by the absence of variation observed on normal eyes. The tendency to diurnal myopisation is rather constant on the whole population studied with a more or less important degree from patient to patient. These observations never reported in the literature, deserve to be confirmed on other sites. CONCLUSION: In this study ICRS allowed to correct low myopia with a satisfactory predictability up to -3.50 D. However, the appearance of an evening myopisation recalls that observed after radial keratotomy. Complementary studies are necessary to explain the intimate mechanism of this phenomenon.

Category specificity in object agnosia: preservation of sensorimotor experiences related to objects.

We report a case of semantic agnosia, characterized by category specificity. Object recognition, mainly involving visual representation, was severely impaired, whereas object recognition involving both visual and sensorimotor representations, was relatively well preserved. His ability to recognize gestures and produce appropriate gestural responses to objects was remarkable. These two factors lead the authors to form a hypothesis, in an attempt to explain the mechanisms involved in object recognition. It has been argued that manipulation of an object may give access to a certain amount of knowledge about it, and that preservation of sensorimotor experiences of objects might be important in recognizing some of them. This could account for the category specificity, described in object agnosia.

Separate visual pathways for perception of actions and objects: evidence from a case of apperceptive agnosia.

Recognition of different kinds of visual stimuli was studied in a patient who acquired apperceptive visual agnosia after a bilateral occipitotemporal lesion which partially spared the primary visual cortex. Impairment in recognising static objects perceived visually sharply contrasts with the relatively well preserved ability to recognise objects from gestures illustrating their use, and to recognise actions shown in line drawings. It is suggested that the occipitoparieto-frontal pathway is involved in the recognition of actions, and in the recognition of objects when sensorimotor experience is evoked.

Optic aphasia: evidence of the contribution of different neural systems to object and action naming.

Visual stimulus naming was studied in a 66-year-old male patient with optic aphasia subsequent to left occipito-temporal infarction. While having difficulty in naming objects perceived visually, he was able to name objects by viewing gestures illustrating their use, and to name actions shown in pictures. These results suggest that naming performance depends on the kind of stimulus that is visually presented (object vs. action). The present findings lend support to congnitive models which postulate the existence of visual and functional semantic systems.

Category-specific anomia: implication of different neural networks in naming.

The occurrence of anomia specifically affecting the ability to name animals is described in three patients. This deficit is contrasted with their capacity to name actions and tools. It is suggested that it is easier to access the names of 'operative' items, which were learned through both visual and sensorimotor experience, than the names of 'figurative' items, which were primarily learned through the visual modality. This hypothesis is consistent with the infero-temporal location of brain damage in these patients. Their ability to retrieve knowledge about operative items is assumed to be due to the sparing of the occipito-parietal area. Because the impairment also involves the recognition of animals, the likely locus of damage is the semantic component of the processing system.

In vitro and in vivo resistance of Leishmania infantum to meglumine antimoniate: a study of 37 strains collected from patients with visceral leishmaniasis.

Primary and secondary unresponsiveness to meglumine has long been described in human visceral leishmaniasis. However, no studies have been performed to elucidate if these therapeutic failures were due to strain variability in meglumine sensitivity or were related to host factors. We have studied the in vitro sensitivity of 37 strains of Leishmania infantum isolated from 23 patients (11 human immunodeficiency virus-infected and 12 immunocompetent patients) with visceral leishmaniasis. Sensitivity tests were performed by infecting murine macrophages with Leishmania parasites and culturing them in medium containing different concentrations of meglumine. For each test we calculated a 50% effective dose (ED50) corresponding to the meglumine concentration at which 50% of the Leishmania parasites survived. In vitro results were strongly correlated to immediate clinical outcome. All strains requiring an ED50 of >70 microg/ml were related to therapeutic failures, whereas all strains requiring an ED50 of <40 microg/ml corresponded to an initial efficiency of meglumine. Among those patients who were initially improved, relapses occurred in all immunocompromised patients and in most immunocompetent patients who had a short duration of treatment (15 days). Finally, we found that in vitro sensitivity of strains decreased progressively in relapsing patients treated with meglumine. Consequently, the physician may be encouraged to alternate meglumine with other treatments such as amphotericin B or pentamidine, especially in the case of relapsing patients.

[Lower limb morphotypes. A clinical study in 1401 children]. / Morphotypes des membres inférieurs. Etude clinique chez 1401 enfants.

PURPOSE OF THE STUDY: The purpose of this study was to analyse the repartition between femoral anteversion and tibial torsion from birth to ten years of age in children. MATERIAL: One thousand four hundred and one children ranging from 2 to 13 years age were examined in public schools by the same clinician. METHODS: Qualitative data (foot progression angle, hindfoot aspect, knee position during gait) and quantitative data (femoral anteversion, tibial torsion) were clinically quantified. RESULTS: Repartition of femoral and tibial torsion showed four lower limb morphotypes in normal children. CONCLUSION: Four femoral anteversion and tibial torsion associations are encountered in normal children. Age variation of the lower limb orientation leed to have repetitive examinations in children with in or out-toeing gait in order to make distinction between normal and pathologic gait pattern.

Utilization of neural network in the elaboration of an evaluation scale for pain in cerebral palsy.

An interesting aspect of neural networks is shown in the elaboration of an evaluation scale for pain in cerebral palsy with severe mental retardation. Because of the diversity of cases, the number of items had to be limited in the final step of statistical validation. Classical analysis on prior data did not allow to decide whether the variability in results is more likely due to the type of disability (i.e., the possibility of pain expression) than to the actual presence of pain. A neural network was used to find implicit relations between the data, with the advantage of having total control on the variables' status by applying variations in the network architecture. This allowed for the rapid identification more significant item combinations as a function of degree of relationship to pain in cerebral palsy.

[Application of artificial intelligence in medicine: automatic analysis of medical reports]. / A propos d'une application de l'intelligence artificielle à la médecine: l'analyse automatique des comptes rendus médico-techniques.

General problems of natural language processing belonging to medical reports are described. The first implementation, reduced to pathologist's reports is proposed. The authors justify their choice according with syntactic grammar and object oriented knowledge representation of semantic. First results are given.

[Neonatal screening for phenylketonuria and hypothyroidism. An optimizing system]. / Dépistage néonatal de la phénylcétonurie et de l'hypothyroïdie. Un système d'optimisation.

Screening for phenylketonuria and hypothyroidism in neonates is currently performed on blood samples collected on the 5th day of life. The efficacy of blood-sampling is evaluated subsequently. Double-sampled and non-sampled children are not always identified. We present a system which provides complete control of child, and was tested experimentally over one year on the 4,260 births in a maternity hospital. The sampling done by the maternity hospital as very thorough: only 0.47% of the children were not sampled spontaneously (ET = 1.07 10(-3)). The sampling of children transferred to pediatric units before the 5th day was a little less rigorous: 6.06% were not sampled before the telephone reminder (ET = 1.86 10(-2)). After a year our system ensured a 100% sampling after identification and telephone reminder for non sampled children, and allowed us to spot and count cases of double-sampling.

[Changes in the kinetics of erythrocyte membrane transport of tryptophan in depression]. / Modifications des cinétiques du transport membranaire érythrocytaire du tryptophane dans les dépressions.

The initial rate of L-tryptophan uptake into human red cells as a function of its concentration in the medium was measured in a group of 8 depressed patients hospitalized included 2 bipolar disorders (296.5x, DSM III), 3 major depressions, single episode or recurrent (296.3x and 296.2x, DSM III) and 3 dysthymic disorders (300.40x, DSM III), which were out of antidepressive treatment, with age ranging from 34 to 64 years compared to a group of 11 healthy volunteers with age ranging from 23 to 54 ans. Kinetic constants were measured at 37 degrees C on red cells incubated with tritiated L-tryptophan and cold L-tryptophan over the concentration range 0.1 to 10 mM. The maximum velocity (Vmax) of the saturable transport is severely lowered in a significant manner in the patients compared to controls (mean +/- s.e.m. = 48.9 +/- 5.5 mumol/l cells/min and 92.0 +/- 14 which represents 47% in decrease). In return, the Michaelis constant is unaffected. The linear component of tryptophan transport, which corresponds to the participation of nonspecific transport systems, is not modified. The possible incidence of such a deficit in the plasmatic reserve of tryptophan in depressed patients on the central availability of serotonin synthesis precursor is postulated.