[Study of the categorization process among patients with eating disorders: a new cognitive approach to psychopathology]. / Etude du processus de catégorisation chez des patientes aux troubles des conduites alimentaires: une nouvelle approche cognitive de la psychopathologie.

Anorexic and bulimic patients have a highly distorted relationship with food and eating, even though they tend to be knowledgeable about diet and nutrition. The progress of this disease, as well as its complications and associated difficulties, are increasingly understood, while the etiopathogeny of eating disorders remains obscure. The approach that we are proposing involves the study of one of the most fundamental cognitive functions of human reasoning--the cognitive process of categorization. The purpose of this study is to understand the procedures used by these patients to construct representations of food. Categorization, one of the basic features of human cognition, allows individuals to organize their subjective experience of the surrounding environment by structuring its contents. This ability to group different objects into the same category based on their common characteristics is important for explaining the major cognitive activities of planning, memorization, communication and perception. Indeed, our categories reflect our conceptions of the world. They depend on our experiences and representations, as well as the expertise acquired in a specific field. The differences that appear in the categories created by subjects when they are asked to classify objects reveal the properties that are most salient to them and, as a result, the interests, values and ideas associated with these properties. There are three types of properties: perceptive properties, which describe the object's shape, color, odor and texture; structural properties, which relate to the object's components; and functional properties, which specify the way in which the object is used and provide an answer to the question, "What is it used for?". Subjects attribute these functional properties by means of knowledge or inference according to their representation of the object's role; such properties are especially likely to emerge during top-down (theory-driven) processing. The type of processing used (bottom-up or top-down) is dependent on a certain number of factors. We hypothesize, within the context of food product categorization, that patients suffering from eating disorders largely resort to processing based on acquired information or beliefs about the objects, i.e. top-down processing. We present two studies: a naturalistic and exploratory pilot study whose goal is to identify whether the various categorization processes used by eating disorder patients differ from those employed by subjects not suffering from an eating disorder. A second study aims to identify the different categorization procedures. During the first experiment, 68 women (17 control subjects, 17 anorexics, 17 anorexic bulimics and 17 bulimics) aged 18-39 (average age: 26.6) verbalize all representations that come to mind during a limited time period as the name of a food item is read. Eighty-nine food items are presented in alphabetical order. The list is read out loud and all comments are recorded. The data is processed in three ways : an analysis based on the positive or negative valence of each representation, an analysis based on each categories of food and an analysis of representations based on themes expressed. The three analyses (valence, categories of food and theme assigned to the representations) show differences between the representations of the four experimental groups. In fact, the anorexics and anorexic bulimics mainly express strongly negative representations about food, whereas bulimics and control produce representations whose positive and negative valences balances. These negative cognitions concern mainly meat for the control subjects and cakes for the subjects reached of TCA. Concerning theme assigned to the representations, the control subjects produce mainly cognitions relating to the hedonism, the flavor of food and their purpose on health. The anorexics and anorexics-bulimics evoke mainly the fat and sugar content of the foods. The bulimics evoke mainly cognitions relating to the effect on health and the intestinal transit time of food. These results lead one to believe that it is not the bulimic binging and purging of these patients, but rather their restrictive behavior that is the determining factor in the differences in food representations observed between the two experimental groups. During the second experiment, 60 women (15 controls, 15 anorexics, 15 anorexic bulimics and 15 bulimics) aged 18-32 (average age: 25.6) classified 27 food names according to their similarities and differences, and then explained the reasons for their categorizations. The data were analyzed in terms of similarity/difference, and the verbalizations were analyzed by content. The results indicate that 10 of the 27 foods were categorized differently by the controls and the subjects with eating disorders. Subjects classified the following foods: camembert cheese, cold cuts, cheese spread, fruit in syrup, whole milk, mayonnaise, bread, fresh fish, potatoes and plain yogurt. Bulimics and controls use similar classifications for food names, while anorexics and atypical bulimics classify foods in a similar way. Examining the categorization criteria used during verbalizations allows us to better understand these differences. The control group's major criterion seems to be the succession of dishes. These subjects group into separate categories entry foods (beef, eggs, fish, etc.), vegetables, cheese or dairy foods, and finally desserts. Additional foods, like bread and mayonnaise, belong to the same category. Other categories are nutritional criteria (for example, dairy products contain calcium) and biological criteria (for example, bananas and apples are fruits). These categorization criteria include structural properties (which describe what the object is made of) and functional, "academic" properties, those which describe how foods are used, "as in cookbooks or diet books." On the other hand, the categorization criteria expressed by anorexic patients are very different from those used by control subjects: foods that are hard to eliminate, rich, high-fat and therefore indigestible are considered to be similar. Some examples are cold cuts, potatoes, mayonnaise and prepared desserts. A second categorization criterion involves the concept of natural foods : certain foods "are unhealthy because they're processed, so they're bad for you"--one such example is cheese spread. A third criterion concerns the notion of familiar foods: poultry and eggs, for example, are "familiar to us." We are clearly seeing here the importance of functional properties in the categorization of food names: certain foods are indigestible, hard to eliminate, cause heartburn or reflux, are not natural, and thus are avoided. The categorization criteria mentioned by bulimic patients also clearly take into account the functional properties of foods. The criteria are of the following type: "it's filling, it relieves a bulimic attack, it helps prevent heartburn and constipation, etc." It appears that bulimics' categorization criteria are solely associated with these foods' imagined or real effect on the body. The categorization criteria used by anorexic bulimics seem to be especially associated with weight gain or the consumption of such foods during bulimia attacks because "they make you feel full." On the other hand, light foods, which patients allow themselves to eat, are placed in the same category. This study, which seeks to understand the cognitive functioning of eating disorder patients with anorexia and bulimia, has brought new elements to light. All patients exhibit food categorization processes that differ greatly from those displayed by control subjects. Patients also attribute greater significance to the functional properties of foods as compared to controls, who give priority to structural properties. Anorexic and bulimic patients base their food categorizations on the consequences of ingestion, in terms of health, digestion and weight gain. Their processing of food stimuli is therefore radically different and gives a dominating place to top-down processes. Additional studies should supplement these findings in order to gain a better understanding of patients' disturbed processing of information.

A calcium-dependent acetylcholine depolarization blocked by methoxyverapamil (D600) and procaine in snail neurones.

1 Repetitive application of acetylcholine (ACh) revealed two types of ACh depolarization in two types of snail neurone, depending on their desensitization properties. 2 Further experiments were carried out on neurones which displayed a rapidly desensitizing response. 3 The amplitude of the response depended on the external sodium and calcium levels. 4 Procaine antagonized ACh effects with the same efficiency as atropine or hexamethonium, half maximal depression being obtained at a concentration of 10(-4) M. The blocking effect was independent of the dose of ACh. 5 The depression of the ACh-induced depolarization by cobalt ions and D600 suggests that calcium may participate in this response.

A new approach to examine the relationships between sensory and gas chromatography-olfactometry data using Generalized Procrustes analysis applied to six French Chardonnay wines.

Six French Chardonnay wines were submitted to both sensory and combined headspace/gas chromatography-olfactometry analyses. The detection frequencies allowed five hierarchical levels to be distinguished: P25, the odorant areas (OAs) having a detection frequency > or =25% (the complete olfactogram without the odor noise); P40, > or =40%; P55, > or =55%; P70, > or =70%; and P85, > or =85%. Moreover, the detection frequencies were analyzed to distinguish 21 discriminative OAs. Wines tested by sensory analysis and the headspace samples analyzed by gas chromatography-olfactometry (GC-O) were described by a heterogeneous vocabulary distributed into nine overall classes of descriptors. The new statistical treatment to examine hierarchical or discriminative OA categories with respect to sensory data used Generalized Procrustes analysis (GPA) from coordinate tables provided by correspondence analysis (CA). The successive data sets supplied by CA were subjected to GPA to yield consensus method maps. The more selective levels of detection frequency (P70 and P85) were responsible for incomplete or distorted information with respect to sensory data. The most appropriate segmentation of the OA distribution (olfactogram) to represent the sensory profile of the six samples would correspond to the intermediate pattern (P40 and P55). The other interest was to study the reasons of distortion due to the dynamic headspace extraction. The highest proportions of the variance were at all times related to the same classes: spicy, herbaceous, and, to a lesser degree, microbiological. This would indicate that the dynamic headspace analysis induces a distortion with respect to sensory data, which systematically affected the perception of both spicy and herbaceous characters of wines.

Depolarizing effect of various local anaesthetics on the Helix aspersa neurons: dose-response relationship.

The depolarizing effect of various local anaesthetics (LA) on the membrane potential of Helix central neurons has been examined. There is a relation between depolarizing effect and concentration of LA in the bath that is linear over a range of concentrations. The slope of the curve is significantly higher for amethocaine (tetracaine) than for procaine while for dibucaine the dose-response relation is not linear. The blockade of a response to acetylcholine (ACh) is about two fold higher for dibucaine and amethocaine than for procaine. These results suggest that both amethocaine and procaine act at the ACh-site in addition to their binding with specific sites located within the ionic channel lumen; dibucaine appears to act through another mechanism.

[Cardiac compression by a large thymic cyst. Apropos of a case, review of the literature]. / Compression cardiaque par un volumineux kyste thymique en bissac. A propos d'un cas, revue de la littérature.

Thymic cysts are rare and almost always asymptomatic. The authors report the case of a 45 year old woman with a thymic cyst diagnosed after recurrent right sided heart failure resulting in signs suggestive of adiastole, regressing after "pleural" (mainly cystic) aspiration and diuretic therapy without any morphological or functional changes on Doppler echocardiography. This report concerns a rare tumour, with an exceptional volume (2 litres) extending down the cardiac borders and causing cardiac compression. It illustrates the diagnostic difficulty of a pathology with an unusual clinical presentation, despite complementary investigations including CT scan and MRI, very sensitive in this type of problem. A complete cure was obtained by total surgical ablation.

[A developmental anomaly of Meckel's cartilage]. / A propos d'une anomalie d'évolution du cartilage de Meckel.

An atypical evolution of the mandibular cartilage was recorded in systematic dissections of the neck in the Anatomy Laboratory. This anomaly led to the formation of a supernumerary bony fragment in the concavity of the lower edge of the mandibular arch, with a slight adhesion thereto. This observation is reported by the authors after a recapitulation of the embryology.

Synaptic connections and functional organization in Aplysia buccal ganglia.

The buccal ganglion of Aplysia contains three morpho-functional groups (A, B, and C) of large cells and two groups (s1 and s2) of small cells. The A cells evoke monoxynaptic IPSPs in the B cells. We found that s1 cells can evoke large EPSPs in the A cells, IEPSPs in the B cells, and EIIPSPs in the C cells; several s1 cells are able to evoke all three types of responses. Many s2 cells can evoke these same responses, but only in the A and B cells. Furthermore, the s cells can evoke depolarizing PSPs in other s cells; this relation is often reciprocal. All these responses may also be contralateral. Their monosynaptic nature is shown by the consistent 1:1 relationship with the presynaptic spike, and also by the effects of intracellular tetraethylammonium and of high Mg2+ concentration in the bathing medium. d-tubocurarine reversibly suppresses the I phase of the IEPSP evoked by the s cells in the B cells. All the responses evoked by the s cells undergo depression with repetition. The network formed by all these relations is outlined, and a double relationship proposed between s cells and B cells. By electrophysiological tracing of axonal pathways it is shown that the A cells send axons into the 3rd buccal nerve, the B cells into the 2nd and/or 3rd buccal nerve and in two cases into the radular nerve, and the C cells into the gastro-oesophageal nerve. Spontaneous synaptic activity of the buccal neurons appears to be formed mostly by the described PSPs. Spontaneous firing inside the isolated ganglion corresponds well to the alternate pattern of muscular contractions of the buccal mass.

Procaine as an acetylcholine agonist in snail neuron.

Low concentrations of procaine (10(-5) M) are capable of provoking changes in the membrane potential of snail neurons. This effect is produced by direct application to the membrane and is characterized by a short response time and rapid reversibility. The resulting potential change has the same properties as that which follows acetylcholine application, including the same change of membrane resistance, the same relationship with membrane potential, the same ionic dependence and, finally, the same pharmacological sensitivity. The identity between the acetylcholine and procaine responses holds both for cells depolarized and cells hyperpolarized by acetylcholine. This procaine sensitivity involves only about two-thirds of the cells and it is concluded that procaine activates the cholinergic receptor on these cells.

Cardiovascular changes during the sleep-wake cycle in spontaneous hypertensive rats and their genetically normotensive precursors.

Blood pressure and heart rate were recorded in spontaneously hypertensive rats (SH) and in their genetically normotensive precursors (WKY) during the sleep-wake cycle using a computer-assisted method. Similar results were obtained in both strains: (a) No significant difference was observed in blood pressure values between slow-wave-sleep (SWS) and the last 2 min of the preceding wakefulness (W) episode within the complete cycle; blood pressure then increased during PS. (b) Heart rate values during SWS were significantly lower than those computed for W; a further fall of heart rate was observed during paradoxical sleep (PS) only in hypertensive rats. (c) During SWS the blood pressure and heart rate variability was significantly lower than during W and PS. In addition, blood pressure variability values during the three sleep-wake states were lower in hypertensive than in normotensive rats. These data suggest that there are no qualitative differences in the mechanisms that control circulation during sleep in normotensive and spontaneous hypertensive rats.

Computer analysis of cardiovascular changes during sleep-wake cycle in Sprague-Dawley rats.

Blood pressure (BP) and heart rate (HR) were recorded in seven Sprague-Dawley rats during a total of 491 normal sleep-wake cycles with the use of a computer-assisted method developed for this study. Significant changes of BP, HR, and BP variability (BPV) were found between the three states within the cycle, i.e., wakefulness (W), slow-wave sleep (SWS), and paradoxical sleep (PS). The highest BP, BPV, and HR values were found during W. Then all cardiovascular (CV) variables fell during SWS, whereas BP and BPV rose again during PS. The fall of BPV observed during SWS was the most important CV change observed within the cycle. These state-dependent CV changes suggest that, in the rat, circulation during the sleep-wake cycle is controlled by the same central factors that operate in cats. In addition, significant BP and HR modifications between different cycles have been found. On the other hand, BP and HR differences between animals were also observed. The latter differences were found to be stable across the states, but no significant relation was found between BP and HR within any state. Thus the present data also suggest that BP and HR measurements are influenced not only by state-dependent factors but also by at least three different factors that are each independent of the state: one leads to BP and HR values that are influenced by the cycle the animal is in and the other two influence, respectively, the ranking of the individual's BP and HR levels within the population.