Remarques sur les parois,l'appareil apical et les réserves nutritives des asques

Sans résuméArticle dédié au Prof. Dr.Lothar Geitler, à l'occasion de son soixantedixiéme anniversaire.     

Observations Biologiques et Ultrastructurales sur les Selenidiidae et Leurs Conséquences sur la Systématique des Grégarinomorphes

SYNOPSIS. The taxonomic position of Selenidiidae Brasil in the class of gregarines is discussed in relation to the study of its life cycles, its possible schizogony and the fine structure of its trophozoites. The cycle of gregarines which belong to the genus Selenidium Giard is characterized by trophozoites with pendular or coiling movements, nuclear transformations in gamonts during syzygy just before cyst formation, anisogamy, sporocysts with 4 sporozoites. Schizogony of the Selenidiidae is not yet demonstrated. The “kystes á meérozoites” within the gut epithelium of Sabellaria alveolata, could be one of the stages of schizogony of S. hollandei. This sole example in our study and the absence of schizogony in numerous species, especially in S. pendula, the type species, shows that this criterion is uncertain, actually, in the definition of the order Archigregarinida Grassé. Ultrastructural studies of S. hollandei and S. pendula show that the cortical region in trophozoites of the genus Selenidium is different from that of Eugregarinida. In the Selenidiidae the epicyte is composed of longitudinal folds. Under the wall, consisting of 3 membranes there is a well-defined pellicular fibrillar system. In S. hollandei, the trophozoite has a fibrillar formation, corresponding to a conoid in its anterior region. The trophozoites of S. hollandei and S. pendula contain anterior dense bodies or rhoptries which are very well developed. All these characteristics conform to the ultrastructural organization of the dissemination forms (merozoites, schizozoites, sporozoites): The results allow one to give a new definition of the Order Archigregarinida: Order Archigregarinida (Grassé): Gregarines with ultrastructural organization of the trophozoites similar to that of dissemination forms. Presence of a well defined pellicular fibrillar system. Intestinal parasites of polychaete worms.     

Veronidia,un genre nouveau des Sphaerioidales et deux champignons parasites sur les feuilles de Vaccinium

Sans résumé     

Contacts, blocages et filiations entre les aires culturelles mésolithiques et néolithiques en Europe atlantique

An examination of lithic industries evolution during VI millenium cal BC shows us transformations of mesolithic technical systems under neolithic pressures, with regional variations. Contrasting classical views, mesolithic groups seems to be less active on atlantic façade than similar groups of France or Spain. This technology transfers are not peripheral phenomenons but testify to intense interactions between mesolithic and neolithic communities, especially on weapons.     

Influence des lecithines dicarboxyliques sur les liposomes

We have investigated the effect of dicarboxylic lecithins on liposomes prepared from egg-lecithins and their incorporation into liposome preparation.In the presence of phospholipids, liposome cell permeability to glucose is five times higher than in controls.The incorporation of dicarboxylic lecithins into liposomes at a molar concentration of 50 molecules per cent reduces by 60% the amount of glucose trapped inside the liposomes.Measurements of ovelecithin-glutaryl-lecithin liposomes stability show that stable structures are formed at a molar concentration of 70 molecules per cent in the presence of cholesterol. On the contrary, the liposomes prepared in the absence of cholesterol are not stable at a molar concentration of 50 molecules per cent.Measurements of sedimentation of mixed dispersions of monocarboxylic lecithins and glutaryl-lecithins show that glutaryl-lecithins must be in the form of micelles to solubilize the phosphatidyl cholines.     

Repartition spatio-temporelle,biomasse et production des populations zooplanctoniques du lac d'aydat en periode estivale

Lake Aydat is a young eutrophic lake (mean depth 7.4 m, area 6o ha) situated in the french Central Massif. Secondary production was studied during the summer months June and July. In early summer, dissolved oxygen in the deep layers gradually gets depleted, and depletion reaches the 7m level in July. Zooplankton is therefore concentrated in the upper layers: Rotatoria are very abundant and the various species are segregated in space and / or succeed each other in time, thus maximally exploiting the water layers favorable to their development. Cladocera are represented by small species, which sharply increase in numbers at the time of maximum primary production, and cause a dramatic drop in primary production. They are in competition with the Rotatoria. Copepods are the least abundant group, but they were in a reproductive phase at the time of this study.88% of the Zooplankton biomass is accumulated in the Cladocera; the Rotifera represent 9%, and the Copepods 8%. Secondary production is intense, and due almost exclusively to filter-feeders in July. Since the carnivores are scarce in numbers, their maximum production is poor relative to that of the herbivores.The P/B coefficient was extremely high during the two summer months, and is indicative of a process of intense consumption of the resources of the lake during that particular short period of the year.     

Activites proteolytiques et anti-trypsine des graines de Vigna unguiculata: Repartition et interaction

Data are given on distribution of caseolytic, BAPA-asic and anti-trypsin activities in albumins and globulins from embryos and cotyledons of Vigna seeds. Embryos are found to be richer in proteolytic enzymes than cotyledons. Trapping of anti-trypsin inhibitors solely enhances the albumin's caseolytic activities. Globulins do not show any BAPA-asic activity. The globulinic anti-trypsin inhibitors are similar on polyacrylamid gels (four fractions) whether the cotyledons or axes are used. The albuminic ones show one fraction more.     

Formation des psychiatres et psycothéraphie: regards croisés sur les situations suisse et française

For more than forty years, psychotherapy belongs formally to the training of Swiss psychiatrists, which is not the case in France. To understand this difference, this article explores the leading role of choices made in the two countries, when specialists’ titles were created. By comparing the creation of the French CES of neuropsychiatry (1949) and the Swiss psychiatrist-psychotherapist’s title, the author emphasizes the importance of institutional aspects. So, unexplored dimensions of the history of psychiatry in these two countries gain some new insight.     

Action des acides caproïque et caprylique sur les mitoses de segmentation chez Triturus helveticus Razoumowsky

Caproic (hexanoic) and caprylic (octanoic) acids 0,01 M (pH 5) are comparatively studied. After 3 hours they do not destroy spindle fibers, but produce several abnormalities classified and hierarchized as follows: 1) bipolar mitoses with inactive poles and blocked centrospheres, 2) mitoses with two dominant poles including centrospheres and secondary poles without them, 3) special pluripolar mitoses with an equatorially dissociated spindle and more or less efficient poles. Partial inhibition of polar activity results in extended hyperfibrillar diastema, which proliferates in fibrillar hollow spheres and burses, but is unable of inducing furrowing. Mechanisms of these disturbances are discussed. Asynchronism and acceleration of polar activity are determined by the absence of the first cleavage. Chromosomal alterations (thickening, deformations and clumping) are partially reversible, but result in chromosomes breakage and recombinations. Stronger activity and toxicity of caprylic acid may be related to its longer carbonic chain.     

Remarques sur les metabolismes respiratoire et fermentaire de Candida kefyr

Study of the metabolic parameters of Candida kéfyr: glucose effect, Pasteur effect. A high fermentation in aerobic condition is observed.     

Influence des radiations lumineuses sur les processus de reproduction des champignons; hypotheses sur l'identite des photorecepteurs. Revue bibliographique

The present review describes the effects of light on reproductive processes in fungi, mainly when action spectra are available.The study of these has resulted in three kinds of photoresponses observable in fungi:

Considerations sur la parabiose des dermatophytes dans les cultures cellulaires

Résumé Dans le but d'étudier l'action des dermatophytes sur les cultures de tissues, les auteurs ont utilisé 18 espèces et des cellules épithéliales humaines (à type de HeLa et Detroit 6) et animale (rein de lapin) et des fibroblastes de l'embryon humain, de poulet et de rat. L'ensemencement des dermatophytes choisis a été faite en des tubes contenant les cultures cellulaires, parfois additionnées de milieu liquide. L'effet protéolytique le plus rapide a été constaté pour les dermatophytes zoophyles, tels queTr. mentagrophytes etTr. quinckeanum et surtout vis-à-vis des cellules HeLa, tandis que les espèces d'origine anthropophyle ont montré une action cytotoxique un peu plus ralentie. Parmi les géodermatophytes, l'action exercée parTr. terrestre etKeratinomyces ajelloi s'approche de celle produite par les espèces d'origine animale, fait qui pourrait plaider, selon l'opinion des auteurs, en faveur de la prochaine adaptation à la vie parasitaire de ces deux derniers champignons. La lyse des cellules obtenue à la suite des produits metaboliques élaborés parTr. megninii fait incadrer ce dermatophyte dans le groupe des espèces d'origine humaine.

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Summary The authors report their first observations on the cytotoxic activity of the dermatophytes inoculated in various tissue cultures. The 18 species of dermatophytes were isolated from different mycotic infections of human and animal origin; the tissue cultures were prepared from different strains of cells: HeLa, Detroit 6, rabbit kidney, human and animal embryos (rat, chicken). The contact of these cells with the dermatophytes induces a lysis which is earliest with the zoophylic species asTr. mentagrophytes andTr. quinckeanum. The geophylic dermatophytes had almost the same proteolytic activity as the human ones, fact that justifies their place in this group of fungi.Moreover the way in whichTr. terrestre andKeratinomyces ajelloi, usually saprophytes of the soil, acted on the tissue culture, as zoophylic species did, enables the authors to consider these fungi (and probably other geophylic dermatophytes), to be adapted to the parasitic life. By this same method of investigation, the problem of human or animal origin ofTr. megninii is studied and discussed.

     

Questions — Réponses sur les dosages des troponines

L’apparition de nouveaux tests de diagnostic cardiologique a profondément modifié l’implication du biologiste dans le diagnostic et le suivi des syndromes coronariens aigus. A c?té des progrès fondamentaux sur la connaissance de la composition, de la structure et de la formation des plaques d’athérome, le biologiste a désormais des outils de diagnostic biologique de la nécrose de qualité analytique supérieure à celle des marqueurs classiques.