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J Médioni

Publications and source records attributed to J Médioni.

15 recordsLinked to original sources
PubMed2004

Wide metastatic spreading in infiltrating lobular carcinoma of the breast.

The aim of this study was to determine whether the metastatic potential of breast cancer could be related to phenotypic characteristics of the tumour. Therefore, we compared the metastatic patterns of invasive lobular (ILC) and ductal (IDC) carcinomas. In ILC, we also analysed this pattern according to the histological subtype of the primary and the E-cadherin (EC) expression level. Metastatic ILC cases (n=96) were retrospectively analysed and classified into classical, alveolar, solid, tubulo-lobular, signet ring cells or pleomorphic subtypes. Anatomical distribution of metastases was detailed for every patient and compared with that registered for IDC (n=2749). Immunostaining of EC (HECD1 antibody) was performed in 82 cases. Histologically, 78 of the 96 cases (81%) corresponded to classical ILC. The pleomorphic subtype was observed in 14 cases (15%), a rate that was higher than that expected. Others corresponded to alveolar (2 cases), signet ring cell (1 case) and solid (1 case) subtypes. EC was undetectable in 72/82 cases (88%). The rate of multiple metastases was higher in ILC (25.0%) than in IDC (15.8%) (P=0.016). Metastases were found more frequently in ILC than in IDC in the bone (P=0.02) and/or in various other sites (peritoneum, ovary, digestive tract, skin em leader ) (P<0.001). In ILC, no significant link was found between the localisation(s) of metastases, the histological subtype and the EC status in the primary. In conclusion, in breast carcinomas, the frequency of multiple metastasis was found to be higher in ILC than IDC. This fact may be related to the phenotypic trait of discohesive small cells which characterises ILC. EC loss, observed in most cases of ILC, may result in alterations in cell-cell adhesion and a preferential growth at metastatic sites. A high rate of pleomorphic tumours was observed in the group of metastatic ILC, but the pattern of metastatic site(s) was not related to the histological subtype of the primary.

Breast Neoplasms↗
PubMed2001

Lipodystrophic syndromes and hyperlipidemia in a cohort of HIV-1-infected patients receiving triple combination antiretroviral therapy with a protease inhibitor.

OBJECTIVES: To assess the frequency and features of lipodystrophic syndromes in HIV-1-infected patients receiving highly active antiretroviral therapy (HAART) with a protease inhibitor (PI), and examine whether clinical and biologic abnormalities are always associated in these conditions. METHODS: Retrospective-prospective single-center observational study of 175 patients. Comparisons for continuous variables by t-test and paired t-test, and Kaplan-Meier analysis of time to onset of lipodystrophy were performed. RESULTS: In all, 51 patients (29%) had morphologic changes, after a mean HAART duration of 20.0 +/- 6.1 months, and were categorized into pure lipoatrophy (n = 16), mixed syndrome (truncal fat accumulation and face or limb lipoatrophy) (n = 30) or pure truncal fat accumulation (n = 5). Because of the small number, the latter group was not analyzed statistically. No differences were found among patients with lipoatrophy, mixed syndrome, or no lipodystrophy, in terms of gender, CD4 count, and HIV RNA plasma load at time of HAART initiation, nor in response to treatment. Patients with a mixed syndrome were older. Patients with lipoatrophy had longer duration of HIV disease, pre-HAART exposure to nucleoside analog therapy, and HAART. Baseline and pre-HAART fasting triglyceride levels were higher in patients who developed lipoatrophy, whereas weight and fasting cholesterol were higher in patients who developed a mixed syndrome. After 12 and 24 months on HAART, triglycerides and cholesterol rose significantly in all patients, independently of lipodystrophy, whereas these parameters were not increased during nucleoside analog therapy. CONCLUSIONS: Nucleoside analog exposure appears as a risk factor for lipoatrophy. Age and nutritional status (reflected by baseline weight, triglycerides and cholesterol) may influence the evolution to lipoatrophy or a mixed syndrome. Hyperlipidemia is observed in the absence of lipodystrophy and depends on PI exposure.

Adult↗
PubMed1998

Acute autoimmune sensorineural hearing loss associated with Crohn's disease.

We report the sudden onset of bilateral hearing loss in a patient with Crohn's disease while the intestinal disease was quiescent. Antibodies directed against collagen type II were detected in the serum. Dramatic improvement of his hearing was observed under corticosteroid therapy. Diagnosis of autoimmune sensorineural hearing loss was established. This condition could be considered as an extraintestinal manifestation of Crohn's disease. Early diagnosis is mandated, as prompt and intensive treatment with corticosteroids and/or immunosuppressive drugs is effective and could prevent irreversible hearing loss.

Acute Disease↗
PubMed1993

Effects of ageing on visual discrimination learning in Drosophila melanogaster.

Two experiments examined conditioned suppression of the Proboscis Extension Response (PER), unconditionally released by sucrose stimulation of gustatory tarsal receptors, in young (7-day-old), middle-aged (30-day-old) and old (50-day-old) Drosophila melanogaster males, reared at 25 degrees C. Individual flies were trained in a differential conditioning procedure in which a white stimulus signalled a quinine reinforcer, whereas a black stimulus was non-reinforced. When trained from the outset with the discriminative procedure, flies of all ages acquired the discrimination, although the acquisition of PER suppression to the white stimulus was retarded in middle-aged and old flies. The retardation of the acquisition of PER suppression in middle-aged and old flies was replicated in a second study in which the files received simple conditioning to the white stimulus prior to discrimination training.

Age Factors↗
PubMed1991

Habituation of the proboscis extension response as a function of age in Drosophila melanogaster.

Habituation of the proboscis extension response induced by sugar tarsal stimulation was individually studied in males of Drosophila melanogaster all along the adult life span (2-71 days of age at 25 degrees C). A polynomial regression fits the best the results: the speed of acquisition of this kind of learning decreases between the ages of 3 and 35 days, a plateau being observed in flies older than 35 days. Similar results have been previously obtained using associative learning tasks of increasing complexity. These effects of age could be due to a memory impairment, but also to deficits in the process of central inhibition of irrelevant motor responses.

Aging↗
PubMed1990

Conditioned suppression of the proboscis-extension response in young, middle-aged, and old Drosophila melanogaster flies: acquisition and extinction.

Young (7 days old), middle-aged (30 days old), and old (50 days old) Drosophila melanogaster males were used in an inhibitory conditioning of the proboscis-extension response. Two reinforcement schedules were applied, constant vs. partial. Partial reinforcement increased the number of trials needed to reach the learning criterion to the same extent in all age groups. Young flies needed fewer trials to reach the criterion than both middle-aged and old flies, which did not differ from each other. Extinction was delayed in the partial reinforcement groups by the same amount in all age groups. The slowest rate of extinction was observed in the old group and the fastest for the middle-aged flies. The results are discussed in connection with hypotheses that consider extinction an index either of behavioral rigidity or of strength of the initial learning.

Aging↗
PubMed1979

A case of behavioral heterosis in mice: quantitative and qualitative aspects of performance in a water-escape task.

Fourteen hundred and four mice from two inbred strains (Balb/c and C57BL/6), F1, F2, and backcrosses were subjected to four trials in a water-escape task and to a swimming test. Detailed analysis of mice behavior in these situations showed that the "F1 hybrid vigor" affected behavioral characters not directly related to physical vigor but of potential adaptive value. Their superiority was mainly due to more frequent adoption of an efficient behavioral tactic (direct or edge escape paths toward the exit) and more rapid progress with experience in this respect than other generations exhibited. These results clearly show that heterosis is not limited to physical vigor but may extend to behavioral and even psychological characters.

Animals↗
PubMed1976

[Further experiments on the conditioning and pseudoconditioning of the tarsal reflex in the drosophila (Drosophila melanogaster): effect of low intensity electric shocks].

In a recently described procedure of negative instrumental conditioning, applied to the tarsal reflex of Drosophila (Médioni and Vaysse, 1975), it was attempted to eliminate some "noise" sources superimposed on the associative conditioning effect. 1) By increasing the preliminary reiteration of the sugar stimulus (US for the tarsal reflex), the suppressive influence of "desensitization" (i.e. sensory adaptation and/or central habituation) could be minimized, at least in the first 20 trials of the training phase. 2) By lowering the intensity of the electrical shock used as an aversive reinforcer, the pseudo-conditioning rate could be substantially reduced too. However the relative weight of the pseudoconditioninq effects could not be decreased by these means: for the effectiveness of the mild shock became weaker for the "true" conditioning as well.

Animals↗
PubMed1975

[Conditional suppression of a reflex in Drosophila melanogaster: acquisition and extinction].

In Drosophila it was possible to carry out a negative instrumental conditioning of the tarsal reflex (extension of the proboscis in response to a sucrose stimulation of the forelegs) : the insects could be trained to inhibit this reaction through a repetitive association of its releasing with a consecutive nociceptive stimulation. An experimental extinction procedure allowed the reflex to be resoted.

Animals↗