Influence comparée de l'(±)-acide abscissique,de la coumarine,de l'acide p-coumarique et de certains de leurs dérivés sur la croissance de la première feuille de blé

Summary The activities of (±)-abscisic acid and a number of compounds derived from p-coumaric acid and coumarin and their interaction with gibberellic acid in the control of the elongation of the first wheat leaf are examined. (±)-Abscisic acid strongly inhibits leaf growth in the presence as well as in the absence of gibberellic acid, but the inhibition is greater in the presence of gibberellic acid (3 g/l already have an observable effect). Among other compounds, only ferulic acid and coumarin significantly reduce leaf elongation, and they are effective only at high concentrations (1.44 · 10^-4 M/l).     

Activité cytokinine de dérivés acylés,alkylés,acyl-alkylés de l'adénine et d'isost`eres azotés de la γ,γ-diméthylallyladénine

The cytokinin activities of various 6-acylaminopurines, 6-alkylaminopurines, 6-acylamino-9-benzyl-purines as well as a series of isosteric-nitrogen derivatives of N⁶-(γ, γ-dimethylallyl)adenine (I⁶Ade) have been tested using the tobacco pith and the pea bud bioassays. The interactions between active, slightly active and inactive compounds have been studied with the last assay. Acylation decreases the biological activity; e.g., N⁶-benzoyl and N⁶-furoyladenines are less active than Na⁶-benzyladenine and kinetin. Substitution at the 9-position reduces (tobacco-pith assay) or suppresses (pea-bud assay) the phytohormonal activity of otherwise active 6-acylaminopurines. In isosteric derivatives, maximum activity occurs when the side chain has the same length as in 1⁶Ade. After the analysis of interactions between more or less active compounds, it is suggested that the differences in cytokinin activity could be related to unequal affinities for a hypothetical receptor site.     

Etude histochimique de quelques hydrolases lysosomiques de l'épithélium intestinal,au cours du développement de la larve de Discoglossus pictus Otth,Amphibien Anoure

Résumé Dans l'épithélium intestinal de la larve du discoglosse, nous avons recherché par le microscope électronique les activités de trois enzymes lysosomiques: la phosphatase acide, la thiolacétate-estérase et l'aryl sulfatase.Avant le climax de la métamorphose, l'activité phosphatasique acide se localise dans des corps au diamètre inférieur au micron, présents dans la zone supranucléaire de l'épithélium primaire. Durant la période climacique (émergence du premier membre antérieur), le produit de réaction diffuse depuis ces lysosomes et occupe le hyaloplasme environnant. Des aires d'autolyse aux limites imprécises apparaissent alors dans l'épithélium. A leur voisinage, on reconnaît de nombreuses vacuoles autolytiques, aux dimensions variées et en général phosphatase acide-positives; elles sont accompagnées de leurs formes d'évolution (corps résiduels) enrichis en tourbillons membranaires; les plus grandes de ces vacuoles pourraient naître après encerclement des aires d'autolyse diffuse. En fin de climax, le phosphate de plomb envahit tout le hyaloplasme, cependant que des fragments cellulaires dégénérés se remarquent dans la lumière de l'organe. Au contraire, l'épithélium secondaire de remplacement est toujours dépourvu du produit de réaction.La mise en évidence des activités thiolacétate-estérasique et aryl sulfatasique confirme la nature lysosomique des corps supranucléaires et des vacuoles autolytiques de l'épithélium primaire.

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Histochemical study of some lysosomal hydrolases of the intestinal epithelium during the development of the tadpole of Discoglossus pictus otth, anuran amphibianII. Observation with the electron microscope

Summary In the intestinal epithelium of the tadpole of the discoglosse, we have analysed the activities of three lysosomal enzymes: acid phosphatase, thiolacetate-esterase and arylsulphatase with the electron microscope.Before the climax of the metamorphosis, the acid phosphatase activity is localized in bodies smaller to one micron in diameter, which are observed in the primary epithelium supranuclear cytoplasm. During the climax (emergence of the first fore-leg), the reaction product diffuses itself from these lysosomes and occupies the surrounding hyaloplasm. Then, autolytic unprecise-limited areas appear in the epithelium. In their neighbourhood, many, more or less large and acid phosphatase-positive, autolytic vacuoles are recognized; they are surrounded by their residual bodies enriched with membrane whorls; the larger vacuoles might appear after segregation of diffuse autolytic areas. At the end of the climax, the lead phosphate invades the whole hyaloplasm; in the meanwhile, cellular degenerated bits are to be seen in the intestinal lumen. On the contrary, the secondary epithelium replacing the primary is always devoid of the reaction product.The visualization of the activities of thiolacetate-esterase and arysulphatase confirms the lysosomal nature of the supranuclear bodies and the autolytic vacuoles of the primary epithelium.

     

Cupule isolée,groupe de cupules isolées,plage de cupules juxtaposées et chevauchantes,nuage de cupules éparses sur les roches gravées de la région du mont Bego. Représentation de l’amas stellaire des pléiades

The protohistoric rock engravings of the region of Mount Bego, located in the Alpes-Maritimes, in the municipality of Tende, include more than 40,000 figurative engravings, such as corniforms, daggers, halberds, axes, reticulates, appendage reticulate, rectangular or oval beaches, anthropomorphs, geometric figures and radiant circles that we consider as an ideogram and more than 60,000 non-figurative signs, such as isolated cupules, isolated cupules of cells, small beaches of cupules, scattered clouds of cupules, bars, which although not figurative are all highly significant. All these engravings, inscribed on more than 4150 rocks spread over 1500 hectares, in eight high mountain valleys, most often made with small cups, were not carried out at random. They have been traced in relation to economic concerns, cosmogonic myths and cultural traditions of the farming and pastoral peoples of the Copper Age and the Early Bronze Age of the Southern Alps during propitiatory rites. It was a period corresponding to the climatic optimum of Chalcolithic where during the summer, in the lower valleys, cultivated fields and pastures dried up. The economic preoccupations of the populations who then occupied the regions located on both sides of the Southern Alps were essentially turned towards the search for water to irrigate cultivated fields and pastures, as evidenced by the petroglyphs inscribed on the rocks: sinuous lines evoking creeks or irrigation canals, rectangular or oval beaches, water catch basins, isolated wells, isolated wells, wells or scattered cups of rain or reticulates, which represent cultivated fields and pastures connected to natural holes or cracks that evoke springs and streams. During propitiatory rites, the engravers addressed the god of the storm, master of the lightning and dispenser of the fertilizing rain, to the great goddess, goddess-mother or goddess-Earth, arms raised in a position of receptivity for collect rain from the sky and bring in spring, with the return of vegetation, abundance to humans.     

Etude histochimique de quelques hydrolases lysosomiques de l'épithélium intestinal,au cours du développement de la larve de Discoglossus pictus Otth,Amphibien Anoure

Résumé Nous avons étudié au microscope photonique les activités de cinq enzymes lysosomiques de l'épithélium intestinal, lors du développement larvaire d'un Amphibien Anoure, Discoglossus pictus Otth. Nous avons visualisé ces activités par le sulfure de plomb (phosphatase acide et thiolacétate-estérase), le sulfate de baryum en contraste de phase (aryl sulfatase) ou par un colorant azoïque (phosphatase acide, -glucuronidase et N-acétyl--glucosaminidase). Avant le climax de la métamorphose, le produit de réaction reste localisé à de petits granules de l'espace supranucléaire. Il envahit l'épithélium primaire au moment du climax (émergence du premier membre antérieur), durant lequel cette assise subit une histolyse. Ce produit est alors présent dans de nombreux corps aux dimensions élevées, assimilables à des cytolysomes (vacuoles autolytiques) ou à des cellules altérées; parfois on le décèle à l'état diffus dans le hyaloplasme. L'épithélium secondaire qui se substitue au primaire ne montre en général aucune activité enzymatique. L'intensité de la réaction varie aussi selon l'enzyme; en particulier, elle demeure faible pour la -glucuronidase mais élevée pour la N-a--glucosaminidase.

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Histochemical study of some lysosomal hydrolases of the intestinal epithelium during the development of the tadpole of Discoglossus pictus Otth, anuran amphibianI. Observation with the light microscope

Summary We have studied with a light microscope the activities of five lysosomal enzymes of the intestinal epithelium, during the development of the tadpole of an Anuran Amphibian, Discoglossus pictus Otth. We have visualized these activities by lead sulfide (acid phosphatase and thiolacetate-esterase), barium sulphate with a phase contrast microscope (arylsulphatase) or by an azo-dye (acid phosphatase, -glucuronidase and N-acetyl--glucosaminidase). Before the climax of the metamorphosis, the reaction product is localized in little granules of the supranuclear cytoplasm. It invades the primary epithelium during the climax (emergence of first fore-leg), while a histolysis of the primary epithelium can be observed. Then this product can be seen in many large bodies which can be explained as cytolysomes (autolytic vacuoles) or as disorganized cells; sometimes too, it can be found in the hyaloplasm. Generally, the secondary epithelium which takes the place of the primary one does not show any hydrolytic activity. The intensity of the reaction also varies with the enzyme; in particular, it remains slight with the -glucuronidase but high with the N-a--glucosaminidase.

     

Charles de Gerville et les premiers restes de Plesiosauria signalés dans le Jurassique inférieur de France (Hettangien,région de Valognes,Manche)

The historian, archaeologist, and naturalist Charles de Gerville (1769–1853) reported as early as January 1816 the presence of fossil bones in the quarries of the region of Valognes, in the department of Manche. These quarries exploited the “Calcaire de Valognes” and the underlying “Argiles et Calcaires d’Huberville”, both formations dated as Lower Hettangian (Lower Jurassic). De Gerville communicated to Jacques-Louis-Marin Defrance a watercolour drawing of one of these fossil bones, discovered in July 1820, in which it is possible to recognize a plesiosaur femur. This femur, as well as a fragment of rib and three vertebrae of Plesiosauria from de Gerville's collection, was then figured in a publication by Arcisse de Caumont, in 1825. The plesiosaur femur was later acquired by Pierre Tesson of Caen, who owned one of the most important collections of fossils in Normandy. The Tesson collection was later purchased in 1857 by the British Museum (now The Natural History Museum, London), where the femur has been rediscovered. This specimen is the first known plesiosaur specimen ever discovered in the Lower Jurassic of France, before the genus Plesiosaurus was established upon material from the Lias of southwestern England. One of the vertebrae figured by de Caumont has been rediscovered in the “Muséum Emmanuel-Liais” (Cherbourg-en-Cotentin), which had acquired part of de Gerville's collection. The interpretation of the “fossil bones of Valognes” by Georges Cuvier, Henri Marie Ducrotay de Blainville, Arcisse de Caumont, Jacques-Amand Eudes-Deslongchamps and Constant Duméril is revealed through unpublished documents.     

Nouvelles données paléontologiques,paléoécologiques et sédimentologiques sur le Berriasien de la région de Lamoricière (ouled Mimoun et E1 Rhoraf,Monts de Tlemcen,Algérie)

In the Western Algerian area, the Ouled Mimoun and El Rhoraf sections are particularly appropriate for the study concerning the berriasian formations.From tha lithostratigraphical point of view, the upper section of the carbonated platform corresponds to the lower Berriasian and a part of the middle Berriasian. The «Argiles de Lamoricière which dominate it belong to the middle and upper Berriasian. The subjacent detritic formation known as «Grès de Berthelot probably begins with the lower Valanginian. The stratigraphical results are based on an abundant fauna (ammonites, ostracods) collected in situ, the main species of which have been the subject of a paleontological review and abondantly illustrated.The studied series offer a good example of the evolution of sedimentary conditions which accompany the temporary opening of a carbonated platform towards the open sea.The variations in fauna composition are closely related to changes in environment. In particular, the presence of ammonites in the Boissieri zone can be connected to the highest point of marine advance, although the depth remained relatively shallow (an upper infratidal zone being likely). It is to note that during this period the low level of sedimentary activity favored the settling of some remarkable epilithic fauna.Above the «Argiles de Lamoricière, the massive detritic sedimentation (grès de Berthelot) could indicate an important paleogeographical change in the interior. In the area studied, the ostracods encountered in the basal section of the last formation still mean a shallow marine environment.     

Apports de la géologie et de la géomorphologie à l’étude du mégalithisme : identifier,interpréter,dater

The contribution of geology and geomorphology to architectural and technological study of the Atlantic coast of France megaliths is important and can be grouped into three main axes: to identify, interpret and dating. Identification refers to the sourcing of the megalithic materiel from 0 to 7 km, sometimes around 10 km, or even exceptionally around 30 km. It is never the entire supply that is affected by such long distances but only a few blocks, some of them are remarkably well staged in the megalithic architecture. Another contribution lies in a fresh look at the management of stone recognized through the modes of acquisition, transformation and use of the raw material. More particularly, the geomorphology associated with technological reading offers tools for recognizing ancient standing stones. In the context of the interpretation of funerary chambers, the two sciences open a large window on the modalities of the internal structuring of monuments. From the entrance to the end of the chamber, the organization and use of the space is documented, sometimes a symbolic coding emerges from the mineral walls. This symbolic coding is based on particular petrography, on surface conditions operating a subdivision of space, on granulometries and homogeneities of differentiated surfaces. The internal organization can also be marked with natural “patterns”, which refer to a completely new aspect of Neolithic thought. Finally, the last axis concerns relative dating, by recognizing forms of postmegalithic fossil erosion, geomorphology makes it possible to identify reused stelae. A very important tool in a current research context where an important episode of reuse of standing stones at the end of the middle Neolithic is anticipated in the construction of dolmens in the south of France.     

Variations de quelques aclivités enzymatiques (peroxydase, catalase, AIA-oxydase) et de la teneur en polyphénols au cours de la germination de I'Orge. Influence de la kinétine

Peroxidase catalase, IAA-oxidase and polyphenol content of growing barley coleoptile. Effect of kinetin. - Kinetin strongly inhibits root and coleoptile growth of germinating barley in the dark. Treated coleoptiles become senescent before the untreated ones. Soluble proteins content, peroxidase, catalase and IAA-oxidase activity were greatly increased in treated coleoptiles while the level of polyphenols was reduced. These biochemical effects joined with the other property of kinetin to diminish α-amylase synthesis in the endosperm are discussed in relation to growth and in connection with the classic view of a cytokinin retarded senescence.     

Distribution spatio-temporelle de la faune de phlébotomes en zones urbaine et périurbaine de Bamako,Mali

Au Mali la leishmaniose cutanée (LC) est bien décrite en milieu rural, mais sa transmission n’est pas encore établie en milieu urbain. L’objectif de l’étude était de décrire la faune phlébotomienne à Bamako et dans ses environs. Les pièges CDC et adhésifs servaient à collecter les phlébotomes en 2011 et 2012 à Bamako. Les pièges étaient placés dans le district de Bamako répartis en 30 zones (200 m × 200 m) à l’aide des images de satellite SPOT-5. La délimitation des zones était basée sur les facteurs écologiques (relief, hydrographie, couverture végétale) et anthropologiques (nature des maisons, dépôts d’ordure). Les pièges étaient placés en 2011 à Sotuba, zone périurbaine, puis à Donéguébougou et Banambani, deux villages environnants de Bamako. Au total 122 phlébotomes étaient collectés 27 (22,13 %) à Banambani, 12 (9,83 %) à Donéguébougou, 2 (1,63 %) à Sotuba et 81 (66,39 %) à Bamako. La densité des phlébotomes en novembre était plus élevée, avec 48 spécimens capturés (39,3 %), que celle d’avril, mai et décembre (p ≥ 0,001). A Bamako, les zones 6 et 28 étaient associées aux densités les plus élevées de phlébotomes respectivement 32 (26,22 %) et 23 (18,85 %) (p ≤ 0,005). Les résultats suggèrent que le genre Phlebotomus n’était pas présent à Bamako, et que la densité des vecteurs variait en fonction des zones et des mois.     

A propos de l'intervention des aéroions dans les processus de régulation de la lipémie et de la cholestérolémie

Resume Les expériences ont porté sur des lapins repartis en deux groupes parallèles — un groupe étant traité avec des aéroions négatifs en concentrations moderées (n^– = 10 – 40.000; n⁺ = 1.000) et l'autre sans aéroionothérapie (témoins). Par rapport aux animaux témoins (pas exposés aux aéroions),on a enregistré,sous l'influence de l'aéroionothérapie, que: (1)il y a une tendence de normalisation de la motilité spontanée, deprimée par une alimentation contenant un excès de cholestérol(0,3 g/kg/jour); (2) la lipémie et la cholestérolémie sont restées à un niveau plus bas chez les animaux alimentés au cholestérol; (3) la lipémie et la cholestérolémie, de même que l'iode thyroïdien, sont restées aux valeurs voisines de celles normales,chez les animaux nourris avec un excès (20 mg/kg/jour), de substances antithyroïdiennes naturelles (provenant du chou).

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Groups of rabbits were exposed to negative air ions of moderate concentrations (n^– = 10 – 40,000; n⁺ = 1,000) while others served as controls. (1) When rabbits were fed a cholesterol-rich diet (0.3 g/kg/day)causing reduction of motility in the control animals, their motility was normalized under air ion treatment. (2) The blood cholesterol and lipid levels of rabbits on a cholesterol-rich diet were lower with air ion treatment than in controls.(3) When rabbits were fed a diet with thyroid blocking agents from cabbage the blood cholesterol and lipid levels and the thyroid iodine content remained unchanged with air ion treatment.

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Zusammenfassung Gruppen Kaninchen wurden mit negativen Luftionen in mässigen Konzentrationen (n^– = 100 000 – 40 000; n⁺ = 1 000) behandelt, während andere als Kontrollen dienten. (1) Die durch Fütterung von cholesterinreicher Diät (0,3 g/kg/Tag) verminderte Motilität der Tiere wurde unter der Luftionenbehandlung normalisiert. (2) Der durch Fütterung von cholesterinreicher Diät erhöhte Blutcholesterin- und-fettspiegel fiel durch Luftionenbehandlung ab. (3) Der durch Fütterung von strumipriven Substanzen aus Kohl erhöhte Cholesterin- und Fettspiegel im Blut und verminderte Jodgehalt der Schilddrüse wurde durch Luftionenbehandlung nicht beeinflusst.

     

Effets de la température sur la croissance de deux algues vertes du fleuve St-Laurent,secteur de Gentilly,Québec

Two abundant phytoplankters from the St-Lawrence river: Scenedesmus spinosus Chodat 1913 and Pediastrum boryanum (Turp.) Menegh (Chlorophyta, Chlorococca) were sampled, isolated and cultured in monospecific culture. Growth responses were measured after acclimation to different temperatures and after thermal shock treatments.Post-acclimation specific growth rates followed similar patterns with optimal temperatures at about 24°C (S. spinosus) and 26°C (P. boryanum). Final densities were much less influenced by temperature in S. spinosus than in P. boryanum. Post-treatment responses depended on the temperature level maintained after treatment rather than on treatment conditions. No treatment seemed to delay the exponential growth phase. The time needed to reach final densities corresponding to stationary growth phase was not influenced by any thermal treatment. In situ thermal effects at Gentilly nuclear site could be more severe, due to differences in time-temperature history experienced by the algae.

     

Mode de formation des lamelles annelées résultant de l'évolution,en condition anhormonale,des ovocytes de Nereis diversicolor (Annélide Polychète)

Résumé L'évolution en l'absence d'hormone cérébrale provoque, dans les ovocytes de N. diversicolor, la formation de lamelles annelées cytoplasmiques (L.A.). Le processus débute par l'apparition de lames de réticulum à proximité du noyau (15 jours d'évolution à 15° C). Les lames se rapprochent ensuite du noyau et des pores apparaissent, situés le plus souvent face à ceux de l'enveloppe nucléaire (20ème jour). La différenciation des lames du réticulum en L.A. progresse ensuite depuis les éléments les plus proches du noyau vers les plus externes.Dans le cytoplasme des ovocytes ayant évolué à la température de 20° C, on assiste en outre à la formation d'empilements de citernes ergastoplasmiques. Ces citernes, non situées à proximité du noyau, subissent également une transformation progressive en L.A.L'étude cytochimique effectuée par digestion enzymatique a montré que la pepsine dégrade fortement le matériel dense des lamelles annelées. Ce matériel semble donc renfermer une teneur élevée en protéines auxquelles pourrait se trouver associé du RNA.

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Mode of formation of the annulate lamellae of oocytes of Nereis diversicolor developing in the absence of brain hormone

Summary Experimental elimination of brain activity leads to the formation of cytoplasmic annulate lamellae (L.A.) in oocytes of N. diversicolor. This process begins with the appearance of cisternae of endoplasmic reticulum in the vicinity of the nucleus (15 days of development at 15° C). Then, the cisternae move closer to the nucleus and pores appear, often facing the pores of the nuclear envelope (20th day). The differentiation of endoplasmic reticulum into L.A. progresses from the elements closest to the nucleus to the more peripheral ones.In the cytoplasm of oocytes which developed at 20° C, stacks of cisternae of rough endoplasmic reticulum have been observed. These cisternae, which are not localized near the nucleus, also undergo a progressive transformation into annulate lamellae.A cytochemical study, based on enzymatic digestion, shows that pepsin strongly digests the dense material of L.A. This material, therefore, seems to contain a high amount of proteins, perhaps associated with RNA.

     

L’industrie du Paléolithique inférieur du site de Wujiagou,Hubei Province,République Populaire de Chine

The site of Wujiagou, Hubei Province in China, dated to just over 800,000 years, in sandy deposits and sandy-silt which covers a river terrace of the end of the Early Pleistocene, delivered a rich lithic industry, mainly composed of pebbles tools. This industry has an archaic aspect, consisted by the abundance of pebbles tools, the presence of hand-axes, and the small amount of small tools. The pebble tools include choppers and picks, in addition of band-axes. Small tools are relatively poor and have few simple retouched scrapers.     

Ultrastructure des disques de patte de drosophile cultivésin vitro. Evagination,sécrétion de la cuticule nymphale et apolysis

Summary Ultrastructural observations were made on imaginal leg discs ofDrosophila cultured in vitro in Mandaron's medium M in the presence of - or -ecdysone.During evagination of discs in vitro the tight epidermal folds of the disc flatten out progressively and the cells change their shape.As the discs evaginate, the pupal cuticle is secreted at the apex of the cells: it comprises a three-layered cuticulin, an epicuticle and a thick endocuticle. Secretion of pupal cuticle always starts by the appearance of dense deposits at the apex of microvilli. Only the latter apparently participate in the construction of the three successive layers of the pupal cuticle.During disc development an abundant rough endoplasmic reticulum is formed. Nuclei and nucleoli become progressively enlarged. At the same time, the nucleus, initially located near the base of the cell, moves closer to the apical cell surface. Microtubules become fragmented as soon as evagination begins and are reorientated parallel to the cell surface (i.e. parallel to the new long axis of the cell) at the end of evagination.

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Ce travail a été réalisé avec l'aide du CNRS (Action thématique programmée) «Différenciation cellulaire», contrat n^o A 6554324.

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Ce mémoire représente une partie de la thèse qui sera soutenue par l'auteur devant l'Université Scientifique et Médicale de Grenoble.     

Étude de deux cent-cinquante souches de bacilles hétérolactiques isolés de vins

Résumé Les auteurs ont isolé plus de 700 souches de bactéries lactiques à partir de raisins, de moûts, de vins de diverses origines et à différents stades de conservation. Ils étudient ici 253 souches de bacilles hétérofermentaires, dans le but d'établir une classification simple et un catalogue permettant un repérage facile des souches.Il est commode de classer les souches d'après la fermentation des pentoses, en raison de la netteté de ces tests, alors que parfois ceux appliqués à d'autres sucres ont des caractères moins tranchés. On retrouve alors la classification qui avait été déjà donnée par Vaughn, Douglas et Fornachon en 1949.Les bacilles pentoses négatifs (26 souches) forment l'espèce Lactobacillus fructivorans. Ceux qui font fermenter seulement l'arabinose (4 souches) ou seulement le xylose (155 souches) correspondent respectivement à Lactobacillus desidiosus et à Lactobacillus hilgardii. L'espèce Lactobacillus brevis comprend les bacilles pentoses positifs (68 souches).

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A study of two hundred and fifty strains of lactic acid bacteria

Summary The authors have isolated more than 700 strains of lactic acid bacteria found in grapes, musts and wines of various origins and at different states of conservation. They study in this work 253 strains of heterofermentative bacilli in order to work out a classification and a catalogue allowing easy identification of the strains.It is convenient to classify the strains from the fermentation of pentoses, on account of the accuracy of these tests, tests on other sugars having sometimes less specific characters. The results are consistant with the classification already established by Vaughn, Douglas and Fornachon in 1949.Pentose negative bacilli (26 strains) constitute the species Lactobacillus fructivorans. The ones which ferment only arabinose (4 strains) or only xylose (155 strains) correspond to Lactobacillus desidiosus and Lactobacillus hilgardii. The pentose positive strains (68) belong to the species Lactobacillus brevis.

     

Effets,sur les potentiels évoqués auditifs précoces,d'un bruit de trafic routier,d'une benzodiazépine et de leur conjugaison

In this study, 30 young men and 30 young women (with the same proportion of anxious persons in each group) were submitted, in random order, to: i) a road traffic noise of 75 dBA for 15 min; ii) this same noise for 15 min, having ingested 0.25 mg of alprazolam (Xanax^*) l h before; iii) uniquely 0.25 mg of alprazolam. The auditory brainstem evoked potentials (ABEP) were taken before and after exposure to noise (for the non-noise case, we respected the same time schedule). The alprazolam had an effect on the cochlea and can be considered as a noise adaptation factor on the auditory pathways explored by the ABEP.     

Expérience de biologie délocalisée,télémaintenance et CQ interlaboratoire...

Dans le cadre de la gestion des analyses urgentes de biologie, le site d’Argenteuil a mis en place une organisation originale (Filière “urgence” mise en place depuis avril 1998) assurant en particulier rapidité et sécurité dans la production des résultats. Nous avons recueilli le témoignage des acteurs principaux à l’origine de cette mise en place.     

Absence de corrélation génotype-phénotype dans les absences de canaux déférents

Absence of the vas deferens is a rare cause of male infertility, associated with mutations in the cystic fibrosis transmembrane regulator (CFTR) gene in about 80% of cases. Only limited published data are available concerning the correlation between genotype and reproductive tract abnormalities observed in this disease: presence or absence of seminal vesicles and parts of the epididymis, symmetrical or asymmetrical lesions, testicular volumes. We screened 47 patients for the 13 most common CFTR mutations on the cystic fibrosis gene and for the 5-thymidine variant of the polythymidine tract of intron 8. Renal, scrotal and transrectal ultrasonography was performed in each patient to explore the testes and reproductive tract. All patients presented absence of the ampullae of the vas deferens. Forty patients presented bilateral absence of the vas deferens and 7 presented unilateral absence of the vas deferens. At least one mutation of the cystic fibrosis gene was present in 64% of cases: 47% had the ΔF 508 mutation and 63% had the 5T allele. No mutation was detected in seventeen patients, including 3 patients with unilateral renal agenesis and 3 patients with unilateral absence of the vas deferens. No differences were observed for seminal vesicles and symmetry of vesicular and epididymal abnormalities between patients with or without CFTR gene mutations, but epididymal abnormalities were significantly more frequent in the group without mutation (p=0.01). Testicular volumes were significantly lower in the patients without mutation or with the 5T allele only, than in the patients with at least one CFTR gene mutation: 10.7±4.1 ml versus 15.1±4.5 ml, respectively (p<0.001). In conclusion, in cases of isolated absence of the vas deferens, there is no difference in sperm duct abnormalities between patients with or without CFTR gene mutation. These results suggest that other genetic or environmental determinants are required to explain a common pathogenesis for these malformations. The decreased testicular volume of patients without CFTR gene mutation or with the 5T allele only suggests the existence of an unidentified secretory or mixed factor involved in these forms of absence of the vas deferens.