Imprégnations rapides à la Nigrosine applicables à la micro-ecologie des surfaces

Summary The ecology of primary biological coatings (fouling films) is an important aspect of benthic ecology in general. Life in a fouling film is, to a large extent, governed by physico-chemical laws of contact surfaces and surface tension. These laws apply also to the microecology of the mesopsammon and surface microplankton. The conditions common to these ecological situations enforce common characteristics, both morphological and physiological, upon the organisms which inhabit them. Many of these organisms are therefore subject to certain general techniques.Nigrosin is employed as an impregnating agent, and the speed of activity of the micelles of nigrosin is under the control of 1) the colloidal nature of the medium, and 2) alteration of cytoplasmic structures by the action of formalin added to the solution as a fixative.The stain blackens a variety of organites having a filamentous ultrastructure: cilia, flagella, trichocysts, rhabdites, cnidocysts, spiny processes of thecae and shells, capsules, cuticles and cuticular setae. The excess nigrosin surrounding the specimen may be removed completely by simple washing.Two particular situations are discussed: that of microbiocoenoses which develop at the point of contact of water and air (for example, bacterial films) and that of glass slides immersed in water with a view to studying the organisms which colonize surfaces in a particular habitat.The method has been applied also for studies of plankton in general, to demonstrate the liberation of flagellate bodies by certain algae, and for preparation of mounts of various organisms such as rotifers, gastrotrichs and nematodes. The method is very useful for quickly obtaining a comprehensive picture of the protozoan fauna in ecological studies.     

Contribution à la connaissance des Hymenoptera Apoidea de Nouvelle-Calédonie et de leurs relations avec la flore butinée

Seulement 21 espèces d’Apoidea sont répertoriées de Nouvelle-Calédonie. La pauvreté de cette faune est paradoxale si on la compare à la richesse et l’endémicité de la flore de l’île, mais s’expliquerait par le fait qu’elle a été isolée avant ou peu après l’apparition des Apoidea vers – 130 millions d’années. Les auteurs comparent aussi les données de plusieurs îles des océans Pacifique et Indien. Deux nouvelles espèces de Halictidae sont décrites: Homalictus cocos et Lasioglossum (Chilalictus) delobeli. Une nouvelle synonymie est établie: Homalictus risbeci (Cockerell, 1929) = Homalictus crotalariae (Cockerell, 1929). Deux taxons, Chalicodoma umbripenne et Megachile laticeps, sont signalés pour la première fois en Nouvelle-Calédonie. Les relations entre les Apoidea et les 22 espèces végétales, sur lesquelles ces insectes ont été capturés, sont présentées et commentées.     

La filiation et l'aide médicale à la procréation

Kinship following artificial insemination by unknown donor defines the child's mother and father as unknown. Although it could have been possible to construct this kinship on the model of adoption, the model adopted was that of blood and organ donation, which completely erases the donor's identity so that the recipient can take complete possession of the donated substance. But is gamete donation the same thing? Gamete donation concerns procreation and the parents' sexuality. Would it be possible to no longer consider the parents' sexuality to be exclusively reproductive sexuality allowing recognition of the progenitors alongside the mother and father?     

Applications à la conchyliculture des récentes acquisitions sur la biologie des mollusques bivalves

Today, mollusc farming represents the fourth part of the mundial aquaculture production. These results have been permitted by the improvement of farming techniques commercially important but also by advances in the biology of a species. Valuable reproductive studies have been carried out in s.a. hatcheries on triploids and tetraploids animals. Since the last decade, advances in the knowledge of metabolism and growth mechanisms has helped the improvement of the brood stock. Nevertheless, the mundial expansion of bivalve farming increases the outbreak of strong epizooties. Investigations allow a valuable knowledge on the scope of molluscan defence mechanisms against pathogen agents. The results are discussed in relation to a possible selection for bivalve farming.     

Les rythmes biologiques des plantes et la biométeorologie

Conclusions Les différents rythmes biologiques des plantes que nous avons passés en revue sont en rapport étroit avec la biométéorologie. Leur étude peut avoir pour but une meilleure connaissance de la biologie, soit qu'on étudie leur rÔle dans l'adaptation au milieu, soit qu'on mette en évidence et qu'on étudie leurs mécanismes physiologiques internes. Mais leur étude peut aussi avoir pour but une meilleure connaissance de la météorologie, si on met en évidence des cycles écologiques mal connus(voir les problèmes de l'influence de la lune ou des taches solaires par exemple) ou bien encore si les observations phénologiques permettent d'étudier la variabilité des cycles écologiques et de caractériser un climat en termes de données biologiques.Ces points de vue sont indissociables quand on approfondit les problèmes; ils n'ont de sens que les uns par rapport aux autres.     

Pratiques funéraires et recrutement : reprise d’étude des collections osseuses issues des dolmens du Languedoc oriental et sud des Cévennes à la fin du Néolithique

Collective burials were the main and most widespread funerary practice at the end of the Neolithic, beginning of the Bronze Age in the south of France. Megalithic monuments required a huge investment of time and labor. According to ethnographic studies, these monumental tombs are generally built and managed collectively. One can therefore wonder who was buried inside these structures because several archaeological studies indicate that access to these tombs can sometimes be restricted to certain members of the population. Indeed, ethnography highlights that access to certain tombs can be structured by variables such as kinship, social status, etc. While previous studies have mainly focused on the architecture and function of these monuments, this article focuses on the process of deposition of human remains and the characterization of the population buried inside these monuments. Since 2012, a project has been undertaken on the dolmens of the south of France in order to discuss funerary practices and to compare them with data from other archaeosciences to rediscuss the funerary traditions in place at the end of the Neolithic, the beginning of the Bronze Age.     

Traumatisme de la verge et des organes génitaux

The most frequent cause of testicular injuries is blunt trauma (following sports injuries or road accidents). Penetrating injuries are rare. Increased scrotal volume and a painful testis are the main symptoms and require scrotal ultrasonography. Scrotal ultrasonography is very sensitive and specific for testicular rupture or intratesticular haematoma. Two out of three patients with testicular injuries require surgical exploration. Secondary complications due to delayed management of trauma are testicular atrophy, sterility or impotence. Penile fracture (rupture of corpus cavernosum) is due to direct trauma by an excessive force applied to an erect penis. Swelling, penile ecchymosis, penile curvature and pain are the usual symptoms of rupture of the tunica albuginea. Urethral injury must be ruled out. Cavernosography, ultrasonography or MRI are not considered mandatory to establish a diagnosis but can be prescribed in the absence of typical signs or symptoms. Early surgical exploration and repair ensure a better outcome. Secondary complications are penile curvature, chronic pain and impotence.     

Contribution à la connaissance des Desmidiées du Congo belge

Résumé Le présent travail s'occupe de 85 Desmidiées, dont la plupart ont été trouvées dans le matériel que j'ai recueilli au Congo, à Stanley-Ville.Quant aux Micrasterias, ce genre a été étudié avant tout sur du matériel provenant des environs de Léopoldville et recueilli par les Docteurs W. Bervoets et Fr. Evens. Une partie des déterminations et des figures ont été faites par le Dr. Evens. Je l'en remercie ici tout spécialement.Les espèces et variétés traitées se répartissent comme suit:Des 85 espèces trouvées dans le matériel examiné, 76 sont nouvelles pour le Congo et 5 variétés sont décrites comme nouvelles pour la science. Ce sont: Pleurotaenium subcoronulatum (Turner) W. & G. S. West, var. maximum Euastrum malmei Borge, var. congolense Micrasterias tropica Nordstedt, var. ndjiliensis van Oye & Evens Cosmarium obsoletum Reinsch, var. glabra Staurastrum orbiculare Ralfs, var. maxima De beaucoup d'espèces des données systématiques sont mentionées et discutées.La dispersion des différentes espèces est examinée là o\u on dispose d'assez de données.Enfin, des conclusions générales sont faites quand le matériel le permettait. En général, les données du travail permettent de confirmer les conclusions faites antérieurement.     

Tests de Selection des Spermatozoïdes avant Assistance Médicale à la Procréation

There are many procedures to select spermatozoa but those procedures are often specific of each andrology centre. This review that is not an exhaustive review of the numerous methods published is rather devoided to focus on the main techniques, the sperm washing, the filtration methods («SpermPrep»), the swim-up, and the discontinuous density gradients with colloïdal solutions («Percoll», PureSperm” and «Isolate») including iodinated organic molecule as ‘OptiPrep». The first part presents a synthesis of literature in order to bring out standardized procedures, and a summary of the advantages and disadvantages of each step of these procedures. Some specific anomalies of sperm need particular treatments. There is a consensus on the validated techniques to prepare semen samples in the presence of antisperm antibodies, leukocytes, bacterial contaminants, and also semen samples exhibiting hyperviscosity or in case of retrograde ejaculation. Cryopreserved sperm preparation is also described with references to experimental results in freezing-thawing human spermatozoa. The second part proposes guidelines for the therapeutic choice of the appropriate assisted reproductive technologies (i.e.: intra uterine artificial insemination, in vitro fertilization or intracytoplasmic sperm injection) according to semen parameters, and to the outcome of sperm selection and survival.     

Contribution à la phylogénie et la systématique des Aleocharinae hypogés d’Afrique du Nord (Coleoptera: Staphylinidae)

A l’occasion de la découverte d’une nouvelle espèce marocaine d’Apteranillus Fairmaire 1854: Apteranillus bichaini n. sp. provenant de l’extrémité occidentale de la chaîne de l’Atlas, de la découverte d’une nouvelle localité d’Apteranillus minosianus Lecoq & Quéinnec 2005 et de la capture du mâle de Typhlozyras camusi Jeannel 1960 jusqu’alors inconnu, toutes les espèces des genres Apteranillus, Typhlozyras et Apteraphaenops Jeannel 1907 sont redécrites et illustrées. Un tableau de détermination et une carte de répartition des genres et des espèces endogées et troglobies d’Aleocharinae d’Afrique du nord (Apteranillus, Anopsapterus, Drusilla (Apteranopsis), Apteraphaenops, Typhlozyras) sont donnés. La synonymie Apteranillus championi Bernhauer 1936=Apteranillus dohrnii Fairmaire 1854 n. syn. est établie. L’examen détaillé des caractères morphologiques des genres Typhlozyras et Apteraphaenops suggère l’appartenance de ces deux genres aux Athetini et non aux Lomechusini comme il est couramment admis jusqu’à présent, Apteraphaenops étant étroitement apparenté à Paraleptusa Peyerimhoff1901 et Typhlozyras à Geostiba Thomson 1858.     

Composition lipidique membranaire durant la préparation de spermatozoïdes à la fécondation

The final modifications that the spermatozoa undergo correspond with the destabilization of their plasma membrane. This indispensable step facilitates the fusion of membranes and primes the signal transduction during fertilization. This destabilization is composed of a series of changes and modulation of the lipids in membranes such as cholestérol, phospholipids and glycolipids. Several differences exist in the lipid composition of the plasma, acrosome, nuclear and mitochondrial membranes of spermatozoa. The principal membrane phospholipids are phosphatidyl choline, phosphatidyl ethanolamine and sphingomyelin. Plasma membrane of sperm is also rich in polyunsaturated fatty acids (PUFA) linked to phospholipids. Such as C₁₈∶2n?6, C₂₀∶4n?6 and large amounts of docosahexaenoic acid (C₂₂∶6n?6). The amount of membrane lipids in human sperm varies considerably between patients. This variation, could influence certain functional properties of the sperm cells such as their ability to undergo capacitation, the acrosome reaction and the fusion between sperm and oocyte membranes. The lipid composition of the human sperm cell can be altered during the process of freezing-thawing. A significant decrease in phospholipids (phosphatidyl choline, phosphatidyl ethanolamine), and PUFA in particular docosahexaenoic acid and arachidonic acid was observed. Human spermatozoa have a molar cholestérol/phopholipid ratio ≤1.0, and reduces during capacitation due to loss of cholestérol. In addition, the decrease in the levels of cholestérol and the methylation of phospholipids is involved in the modification of membrane fluidity and in the maturation of the sperm plasma membrane receptors. Therefore it seems that the methylation is important for the fusion between sperm and oocyte membranes. Intrinsic sperm phospholipase A2 also plays a role in the destabilization of the plasma membrane by producing of lysophospholipid. Therefore this enzyme and free fatty acids are believed to play a role in the acrosome reaction, an indispensable event facilitating the fusion between sperm and oocyte membranes.     

Cytochrome P450 et activation génétique — de la pharmacologie à l’élimination du cholestérol et à la régression de l’athérosclérose

Background

Lipoproteins are closely associated with the atherosclerotic vascular process. Elevated levels of highdensity lipoprotein cholesterol (HDL-C) and apolipoprotein AI (apo AI) in plasma indicate a low probability of coronary heart disease (CHD) together with enhanced longevity, and elevated levels of low-density lipoproteincholesterol (LDL-C) and apo B indicate an increased risk of CHD and death. Studies linking gene activation and the induction of cytochrome P450 with elevated plasma levels of apo AI and HDL-C and lowered plasma levels of LDL-C presented a new potential approach to prevent and treat atherosclerotic disease.

Objective and methods

This is a review aimed at clarifying the effects of P450-enzymes and gene activation on cholesterol homeostasis, the atherosclerotic vascular process, prevention and regression of atherosclerosis and the manifestation of atherosclerotic disease, particularly CHD, the leading cause of death in the world.

Results

P450-enzymes maintain cellular cholesterol homeostasis. They respond to cholesterol accumulation by enhancing the generation of hydroxycholesterols (oxysterols) and activating cholesterol-eliminating mechanisms. The CYP7A1, CYP27A1, CYP46A1 and CYP3A4 enzymes generate major oxysterols that enter the circulation. The oxysterols activate — via nuclear receptors — ATP-binding cassette (ABC) A1 and other genes, leading to the elimination of excess cholesterol and protecting arteries from atherosclerosis. Several drugs and nonpharmacologic compounds are ligands for the liver X receptor, pregnane X receptor and other receptors, activate P450 and other genes involved in cholesterol elimination, prevent or regress atherosclerosis and reduce cardiovascular events.

Conclusions

P450-enzymes are essential in the physiological maintenance of cholesterol balance. They activate mechanisms which eliminate excess cholesterol and counteract the atherosclerotic process. Several drugs and nonpharmacologic compounds induce P450 and other genes, prevent or regress atherosclerosis and reduce the occurrence of non-fatal and fatal CHD and other atherosclerotic diseases.     

Effets d’une exposition à la Vinclozoline et à la Génistéine de la gestation à l’âge adulte sur la fonction de reproduction du ratWistar mâle: protocole et résultats préliminaires

Current evidence indicates that endocrine disrupters (EDs) can induce adverse effects on the male reproductive tract in various mammalian species. Recent reports indicate deterioration in male reproductive health in several human populations, but the evidence for a causal link with endocrine disruption is still weak. In addition, the experimental conditions of most of the reportedin vivo studies are not representative of environmental exposures (for example, high doses, short-term exposure, a single ED) and the mechanisms by which EDs disrupt the reproductive system are poorly understood. The objective of the present study is to develop an animal model to assess the reproductive effects and study the putative cellular and molecular mechanisms involved after exposure to genistein (phytoestrogen) and vinclozolin (fungicide with a known antiandrogenic potential) alone or in combination. The study will be performed in male Wistar rats, with administration of low and high doses of the compounds from conception to adulthood and a subset of the males in each treatment group will be mated with unexposed females. We plan to assess the level of sperm production, histology of the reproductive organs, motility and morphometry of spermatozoa and hormone levels, as well as DNA fragmentation of spermatozoa and determination of the number of germ cells, Sertoli cells and the diameters of seminiferous tubules. Estrogen, androgen, progesterone and FSH receptors will be detected and quantified and the level of testicular apoptosis and several apoptosis pathways will be studied to determine the putative cellular and molecular mechanisms involved. The preliminary results confirmed the developmental effects previously reported for high doses of vinclozolin. More interestingly, they indicated a number of deleterious effects for male rats exposed to low dosages alone or mixtures of low and high dosages compared to controls and rats exposed to high dosages alone. For example, a number of developmental anomalies of the genitalia were observed and a significant decrease of sperm motility and motion and fertilizing ability were observed. These preliminary results provide evidence that chronic exposure to environmental levels of EDs or mixtures of EDs have a detrimental impact on the male reproductive tract. The next step involves assessment of the anatomical disorders and the study of some of the cellular and molecular mechanisms possibly involved.     

Le cystadénome des vésicules séminales : à propos d’un cas et revue de la littérature

The primitive tumors of seminal vesicles are rare. Almost one hundred cases were reported in the literature. This is most often benign tumours with cystadenomas, primary malignant tumours are too rare.We relate a new case of tumour of the left seminal vesicle with a 70 years aged patient discovered next to an acute retention of urine associated with a constipation. The diagnosis was confirmed by imaging (CT and IRM) that showed a large multi-cystic mass of the left seminal vesicle. The treatment was surgical (vesiculectomy) preceded by a suction drainage of the mass. The anatomopatholgic exam of surgical piece has reached to a cystadenoma of the left seminal vesicle. Throughout this observation, we discuss the different clinical, radiological, histological and therapeutic aspects of seminal vesicles tumours.