Personnalisation des émotions et cortex médial préfrontal

Functional brain imaging studies in healthy subjects suggest that several regions (prefrontal cortex, amygdala, thalamus, hippocampus, anterior cingulate) have specialized functions for emotional operations. Within these regions, the medial prefrontal cortex (MPFC) is considered to have a general role in emotional processing. Using a memory paradigm with verbal material, we recently demonstrated that the MPFC is specifically involved in self-related processing of emotional stimuli. Study with mood induction also suggest that personality traits may modulate the reactivity of the MPFC to emotional Stressors. Taken together these findings support the hypothesis that the MPFC subserve processes involved in emotion regulation. Dysfunction of the MPFC and related structures (i.e. amygdala) may increase the vulnerability to emotional disorders.     

Identification par immunofluorescence des cellules corticotropes et mélanotropes de l'hypophyse des Amphibiens

Résumé Les antisérums préparés à l'égard de trois hormones de synthèse [β(1–24) corticotropine, α et β MSH] nous ont servi pour localiser par immunofluorescence dans l'adénohypophyse des Amphibiens les sites d'élaboration de l'ACTH, de l'α et de la β MSH. Les anticorps anti-α et anti-β MSH se fixent exclusivement sur les cellules de lapars intermedia tandis que l'anti β-(1–24) corticotropine révèle simultanément une catégorie de cellules de lapars distalis et des cellules de lapars intermedia. D'après le contr?le cytologique effectué par la technique au bleu Alcian PAS, l'ensemble de ces cellules sont PAS positives et bleu alcian négatives. Elles réagissent également à la paraldéhyde fuchsine en l'absence d'oxydation permanganique. La signification de ces résultats est discutée.

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Identification by immunofluorescence of the corticotropin and melanotropin cells in Amphibian pituitary

Summary Antisera prepared against synthetic β(1–24)corticotropin (synacthen) α and β MSH were used to localize, by immunofluorescent procedure in the adenohypophysis of Amphibians, the site of production of ACTH, α and β MSH. Anti-α and anti-β MSH antibodies appeared to be bound only to thepars intermedia cells whereas anti-β(1–24) corticotropin reacted simultaneously with specific cells of thepars distalis and cells of thepars intermedia. Cytological control by alcian blue (pH 3) PAS technique proved that all these cells are PAS positive and alcian blue negative. They react also with paraldehyde fuchsine without oxidation. The possible significance of these results is discussed.

     

Nouveaux traceurs TEMP : exemple des traceurs des protéoglycanes et de la mélanine

The majority of research program on new radiopharmaceutics turn to tracers used for positron emission tomography (PET). Only a few teams work on new non fluorine labeled tracers. However, the coming of SPECT/CT gamma cameras, the arrival of semi-conductors gamma cameras should boost the development of non-PET tracers. We exhibit in this article the experience acquired by our laboratory in the conception and design of two new non fluorine labelled compounds. The ^99mTc-NTP 15-5 which binds to proteoglycans could be used for the diagnosis and staging of osteoarthritis and chondrosarcoma. The iodobenzamides, specific to the melanin, are nowadays compared to ¹⁸F-fluorodeoxyglucose in a phase III clinical trial for the diagnosis and detection of melanoma metastasis. Our last development focus on BZA heteroaromatic analogues usable for melanoma treatment.     

Distribution et activités des alcaloïdes défensifs des Coccinellidae

From a survey of 30 species and varieties of ladybugs the presence of alkaloids appears to be correlated with the existence of aposematic colour and not with being carnivorous or phytophagous. The alkaloids described until now all belong to the Coccinellini and are closely related, but other types of bases have been detected in some genera. The observed distributions are in agreement with the modern taxonomy of the family.Ladybug alkaloids constitute an effective defence against ants, Myrmica rubra, and quails, Coturnix coturnix, but all the beetles containing alkaloids do not possess the same degree of protection. Individual quail react differently towards moderately protected species.The bioassay used for the first isolation of coccinelin is described. The repulsive activities of aqueous solutions of coccinellin and convergin towards ants have been compared.     

La potomanie: réévaluation des epreuves d'investigation et présentation inhabituelle avec hydronéphrose et méqavessie

Three cases of compulsive polydipsia previously diagnosed as diabetes insipidus are presented. Abnormally dilated bladder and pyelocalyceal systems were accompanying features, as previously described for diabetes insipidus, particularly of renal orign. Results of the hypertonic saline (Hickey-Hare) test were positive in only one case. Results of restriction of liquids followed by intravenous injection of vasopressin (Miller test) favoured a diagnosis of complete diabetes insipidus. These two tests cannot, therefore, exclude compulsive polydipsia. The features suggesting a diagnosis of compulsive water drinking are low plasma osmolality, a decrease in 24-hour urine output following water restriction, and abnormal behaviour. The diagnosis is confirmed by an 18-hour dehydration test done after gradual fluid restriction, which favours partial restoration of the papillary osmotic gradient.     

Chromosomes et hétérochromosomes de ténébrionidés

Sans résumé Avec 81 figures dans le texte     

Localisation cytologique par immunofluorescence des sécretions corticotropes, α et β mélanotropes au niveau de l'adénohypophyse des bovins,ovins et porcins

Résumé Les sites d'élaboration de l'ACTH, de l'-MSH et de la -MSH ont été recherchés par immunofluorescence à l'aide de sérums préparés contre l'-MSH, la -MSH bovine et la -(1–24) corticotropine synthétiques. L'absence de réaction croisée entre ces différents antigènes conduit à admettre que, dans les espèces testées (bovins, ovins et porcins), les cellules du lobe intermédiaire élaborent simultanément l' et la -MSH, tandis que les cellules corticotropes du lobe antérieur secrètent l'ACTH et la -MSH, l'-MSH étant absente de la pars distalis; la spécificité de la réaction paraît due à l'absence de déterminants anticorps dirigés contre l'heptapeptide commun à ces trois hormones polypeptidiques.

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Immunofluorescent localization in adenohypophyseal cells of corticotrophic and - and -Melanotrophic secretions in the cow, the sheep, and the pig

Summary The sites of production of ACTH, -MSH, and -MSH were studied by immunofluorescence using antisera prepared against synthetic -MSH, bovine -MSH and -(1–24) corticotropin. The absence of cross-reactions between the different antigens lead us to conclude that, in bovine, ovine and porcine species, the cells of the intermediate lobe produce - and -MSH simultaneously, while the corticotrophic cells of the anterior lobe secrete ACTH and -MSH (-MSH is absent in the anterior lobe). It seemed that the specificity of the secretion is due to the absence of antibody determinants against the hepta-peptide, common to the three polypeptide hormones.

1 Abréviations utilisées: MSH: Melanocytes Stimulating Hormone; ACTH: Adrenocorticotrophic Hormone; PAS: Periodic Acid-Schiff (reaction d'Hotchkiss Mac-Manus); Ac.: Anticorps; Ag. Antigène; C: Complément.     

Psammocarcinome ovarien et médecine nucléaire

We report three cases of ovarian psammocarcinoma, which is a serous adenocarcinoma having psammoma calcifications. The FDG uptake in the psammomatous lesions is due to the tissular part of the lesion and the technetium-99m labelled agents uptake to its calcified part. Calcifications are detected on CT scans. Therefore, they are relatively simple to diagnose by nuclear medicine which is useful given relatively the better prognosis of the psammomatous ovarian serous carcinoma when compared to the serous one.     

Apoptose et ségrégation méiotique dans les spermatozoïdes d'hommes porteurs de translocations

Men with a chromosomal translocation produce a significant percentage of unbalanced spermatozoa. In order to determine a correlation between chromosomal anomalies and apoptosis in human sperm, we analysed DNA fragmentation and meiotic segregation in sperm from men with a (13;14) Robertsonian translocation. We studied sperm from 12 (13;14) translocation carriers and 9 proven fertile men with a normal karyotype. Meiotic segregation of chromosomes 13 and 14 was analysed using dual-colour fluorescencein situ hybridization with locus-specific probes for chromosomes 13 and 14. Apoptosis in spermatozoa was measured byin situ TUNEL assay. The meiotic segregation study showed a significantly increased frequency of unbalanced spermatozoa for chromosomes 13 and 14 in (13;14) carriers (15.9%) compared to the control population (1.3%) (p=0.00016). The study of apoptosis showed an increase of DNA fragmentation in (13;14) carriers (34.9%) compared to the control population (13.8%) (p=0.0036). This increased apoptosis was observed in spermatozoa presenting an increase of unbalanced chromosomal anomalies concerning chromosomes 13 and 14, but with a predominance of balanced spermatozoa compared to the theoretical risk of meiotic segregation. These results suggest that apoptosis could be involved as a regulatory mechanism to eliminate unbalanced chromosomal spermatozoa in men with a (13;14) Robertsonian translocation.     

Intérêt potentiel des images paramétriques des temps d’éjection et de relaxation en tomoscintigraphie des cavités cardiaques dans l’évaluation des cardiopathies asynchrones

Intraleft dyssynchrony is strongly correlated to contractile dysfunction associated to severe heart failure. Dyssynchrony is also a predictive marker for cardiac resynchronization therapy response. We measured dyssynchrony values for both ventricles from gated blood pool SPECT images.Material and methodsThree groups of patients were sampled from normal patients (n = 7), mild heart failure patients (n = 24) and severe heart failure patients (n = 9). Time-derivative parametric images were obtained from 24-time bins gated blood pool SPECT data. We measured intraleft and interventricular contractile and relaxing dyssynchrony values from these images.ResultsIntraleft dispersions values linked to ventricular peak emptying rate were 107 ± 21 ms, 141 ± 58 ms and 515 ± 104 ms for each of the three groups. The values linked to left ventricular peak filling rate were 122 ± 62 ms, 219 ± 117 ms and 603 ± 164 ms respectively. Statistical significant differences (p < 0.01) were observed both for contractile and relaxing phases for severe heart failure patients. Mild heart failure patients had isolated statistical significant (p < 0.01) alterations of the ventricular relaxing phase. Correlation between isotopic dyssynchrony values and left ejection fraction led to a R square coefficient of 0.71 and 0.64 for time to peak emptying and to peak filling respectively. Correlation to QRS width values led to a R square coefficient of 0.76 and 0.62 respectively.ConclusionVentricular dyssynchrony correlated to the importance of the ventricular mechanical dysfunctions is a robust predictor of heart failure. Separate analysis of contractile and relaxing dyssynchrony may lead to a better understanding and characterization of the mechanical dysfunctions involved in heart failure.     

Mort programmée des cellules germinales testiculaires: causes et mécanismes mis en jeu

Spermatogenesis results from a balance between proliferation and apoptosis. An alteration in this balance could lead to testicular diseases such as testicular tumour or infertility. Apoptosis seem to be important in regulating the processes of spermatogenesis since 60 to 75% of germ cells do not reach the spermatozoa stage. The various molecules of the apoptotic cascade have been detected in rodent or human germ cells, such as effector caspases and upstream proteins from cell death receptor or mitochondrial pathways. One or several different pathways may be involved in the germ cell apoptotic process triggered physiologically, by hormonal deprivation, or by chemical or physical inducers. Finally, caspases appear to play a role in various testicular diseases (particularly infertility).     

Résumés des communications orales et affichées

XVIème Congres de la Societe d’Andrologie de Langue Francaise Issy-Les-Moulineaux 9-11 Décembre 1999

Résumés des communications orales et affichées