Observations sur la significativité de la coloration aux Alcians pour les mucopolysaccharides

Resumé Les Auteurs, à la suite d'une serie des récherches sur la coloration au bleu Alcian de la cartilage, on pu démontrer que la signaléticité de ce colorant basique envers les mucopolysaccharides est due à la interférence inhibitive avec une fraction protéique présente en grande quantité dans les structures non-mucopolysaccharidiques ionisées au pH de utilisation (2,4) (DNA, collagéne etc.), fraction bien soluble dans les solutions salines et dans l'acide sulphurique 1 M, mais peu soluble dans l'acide acétique 3%.L'asportation de cette substance à l'aide de dits solvants ou de la digestion à la pepsine, augmente la colorabilité des mucopolysaccharides, mais diminue ou abolit la signaléticité.Sur cette donné, les Auteurs expliquent les differentes anomalies de la méthode aux Alcians.

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Observations about electivity of Alcian staining of mucopolysaccharides

Summary The Authors proved, in the course of a general investigation about the Alcian blue staining of cartilage, that the specificity of this dye is due to its inability of staining in the presence of a proteic fraction, which is present in a greater amount in the non-glycid structures containing ionized groups at 2,4 pH: i.e. collagen, DNA etc.This protein is easily soluble in various salt solutions and in 1 M sulphuric acid, but insoluble in 3% acetic acid. Removal of this protein by these agents or by peptic digestions result in increasing the mucopolysaccharides staining, but in decreasing or suppressing electivity.Differents abnormalities of Alcian method are explained by the Authors in this way.

     

Sur la spécificité deVagoiavirus melolonthae

Summary The activity ofVagoiavirus melolonthae towards 16 species ofScarabaeidae, 3 Coleoptera, 3 Lepidoptera and 2 Diptera was studied by injection into the hemocoel and contamination of the substratum or of the rearing host plant. Only insects belonging to 3 sub-families ofScarabaeidae: Hopliinae, Melolonthinae, Rutelinae, are susceptible to the disease.      

Influence de pH acides sur la viabilité d'isolats deFrankia

Résumé Vingt souches deFrankia, isolées à partir de 7 espèces différentes de plantes actinorhiziennes ont été cultivées sur des milieux maintenus à des pH constants de 5; 4,8; 4,6 et 4,2. Chaque souche a été cultivée 2 à 3 fois consécutives à un même pH. Quatorze souches ne montrent aucune croissance à pH 5. Seules 3 souches résistent à un séjour de plusieurs semaines à pH 4,6. Aucune souche ne demeure viable après un séjour dans un milieu à pH 4,2. Les 3 souches acido-résistantes supportent également la présence d'Al⁺⁺⁺ libre dans le milieu de culture. Une forte concentration d'H⁺ dans le milieu stimule beaucoup la sporogénèse. Inoculée dans un sol acide une souche acido-résistante conserve une chance de survie nettement supérieure à celle d'une souche neutrophile maintenue dans les mêmes conditions.      

Contribution a l'étude de la spécificité chez les principales coccinelles aphidiphages des alpesmaritimes et des basses-alpes

Summary The present work is a field study of seven species ofCoccinellidae suitable for use in the biological control of aphids in cultivated areas of South Eastern France. The distribution of larvae and adults has been studied all the year long in the different geographical areas where aphid pullulations occur and according to the different types of plants. Sampling units have been distributed in five different ?strata? classified A, B, M, N, V, on the basis of height: from 0 to 50 cm low plants: A. wild B. cultivated. from 50 cm to 2 m shrubs: M. wild N. cultivated. more than 2 m trees: V. wild or cultivated together. The adults ofCoccinellidae are able to disperse widely but they show a strong preference for a given type of habitat; they are generaly able to feed on a great number of species of aphids but many of these do not allow egg production or larval nutrition. These factors have been studied in the laboratory. One of the results of this study is to give an idea of the potentiel efficiency of the different monovoltin or polyvoltin species present in the area during the successive periods of the year. Spatial limitation as a consequence of the action of ecological factors is the most characteristic feature of the behaviour of coccinellid predators; its influence on specificity is greater than the actual choice of a given host as a food.      

Observations sur la végétation de la zone littorale en Provence

Sans résuméReçu par la rédaction le 1.VII.1953.     

Influence de la température sur la cinétique,de croissance et le coefficient de maintenance de Candida lipolytica cultivé sur n-alcane

The effect of growth temperature on the evolution of kinetic parameters and yields was determined for Candida lipolytica cultures with ntetradecane as substrate, in a temperature range of 18°C to 30°C, which is below the critical growth temperature in order to work only in the activation zone of these parameters.In such a culture limited by substrate transfer, growth rate depends on biological rates, related to microorganisms characteristics, and diffusional rates, related to mass transfer. The effect of temperature thus depends on the limiting step. The activation energy, calculated from exponential growth rate determinations is .When the activation energy is calculated from the maximal rate of cell production (determined at the growth curve's inflexion point), it's found to be E _X=71,200 J/mole in the 18°C–24°C range, and E _X=28,000 J/mole in the 24°C–30°C range. The latter one is characteristic of a diffusion-limited process. Above 24°C, growth is controlled by substrate-transfer, as physiological potentialities are preferentially increased with temperature than diffusional ones: 24°C is thus the transition temperature T _t from physiological to diffusional limitation.The apparent yield is almost constant, over the 18°C to 30°C temperature range, although maintenance coefficients are very dependent on temperature. The activation energies related to maintenance coefficients for alkane and oxygen respectively are and .The m _s/m_{O 2} ratio is about 3 (g/g), whereas that, for a strict oxidation reaction of n-tetradecane ought to be 3.47 (g/g). A satisfactory correlation, relating maintenance coefficients to the maximal growth rate of yeast, is given.

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Liste des symboles A constante de saturation de modèle de croissance(1) - B vitesse spécifique considérée - C substrat carboné ou oxygène (g/l) - E energie d'activation (J/mole) - S _m quantité de substrat consommée par maintenance au cours d'une fermentation discontinue (g) - O₂ quantité d'oxygène transférée au milieu de culture (g/l) - R rendement global de la fermentation - R rendement global de la fermentation - constante des gaz parfaits (J/mole K) - S concentration en substrat carboné (g/l) - T température de croissance (°K) - X concentration en biomasse (g/l) - Y rendement limite - m coefficient de maintenance (h^-1) - t duree de fermentation (h) - tømpérature de croissance (^o Celsius) - taux de croissance (h^-1) Indices 1 relatif à la température 1. - 2 relatif à la température 2 - c relatif au substrat carboné ou à l'oxygène - f relatif au temps final - i relatif au point d'inflexion - m maximum - mO₂ relatif au coefficient de maintenance sur l'oxygène - m _s relatif au coefficient de maintenance sur le substrat carboné - o relatif au temps initial - O₂ relatif à l'oxygène - s relatif au substrat carboné - t de transition - T relatif à la température de croissance T - U _m relatif au taux de croissance maximal - X relatif à la productivité maximale en biomasse     

Conséquences de la chimiothérapie anticancéreuse sur la fertilité de la femme

Sterility is a potential toxic effect of chemotherapy. This risk is well established for alkylating agents, but is less clearly defined for anthracyclines, methotrexate and fluorouracil and poorly defined for alkaloids, platinum, etoposide and taxanes. The main predictive factors for ovarian toxicity are the additive effect of cytotoxic drugs, the cumulative dose of each drug and the patient’s age. This effect of chemotherapy is evaluated on menstrual cycles, hormonal assays and the number of pregnancies observed in patient cohorts. Chemotherapy induces destruction of oocytes and granulosa cells. In mice, it has been shown that adriamycin may induce oocyte apoptosis, which can be prevented by modulation of cycle cell signalling (dysregulation of Bax gene or, on the contrary, expression of its antagonist gene Bcl-2 or inhibition of apoptosis with sphingosine-1-phosphate or caspase inhibitors). Clinical data in the literature are usually based on retrospective studies and are somewhat confused: global fertility after MOPP chemotherapy for Hodgkin’s disease is about 20%, adjuvant chemotherapy with CMF, F(A)C or TAC for breast cancer induces amenorrhea in 50% to 70% of cases, PVB or BEP chemotherapy for ovarian germ cell tumors has little effect on fertility when the uterus and one ovary can be preserved, and the majority of women treated with methotrexate, actinomycin D or various combinations for persistent trophoblastic disease remain fertile. Preservation of fertility is a major goal for cancer patients receiving chemotherapy: in vitro fertilization could preserve the couple’s fertility, but is usually not feasible as it would delay initiation of chemotherapy until after stimulation of ovulation; oocyte or ovarian tissue cryopreservation is at the stage of research; oral contraceptives have not been demonstrated to be effective to preserve ovarian function; gonadotropin releasing hormone (GnRH) agonists prevent cyclophosphamide toxicity in rat and monkey ovaries, and a few pilot clinical studies suggest that chemotherapy-induced amenorrhea could be prevented by administration of GnRH analogues simultaneously to chemotherapy, but randomised studies are necessary.     

Observations sur la microflore fongique des feuilles vertes et sénescentes de Loudetia simplex

Abstract

Observations on the mycoflora of green and senescent leaves of Loudetia simplex.—Leaves of Loudetia simplex, a common grass of the moist savannah of Ivory Coast, were collected at different growth stages at the end of the life cycle (December) and during the growing period of the plant (June). The study was carried out by indirect techniques, plating on PDA in Petri dishes aliquots of a suspension 1:1000 (fresh weight/volume) of ground leaves.

The isolates belong mainly to Fungi Imperfecti; the distribution of the Fungi includes 20 Moniliaceae, 13 Dematiaceae, 15 Tuberculariaceae, 4 Melanconiales, 9 Sphaeropsidales, 1 Ascomycetes and a number of sterile hyphae, mainly with dark mycelium.

Most of the isolates are commonly recorded on leaves (Cephalosporium acremonium group, Cladosporium cladosporioides, Fusarium spp., Monodictys, Phoma). Also present Nigrospora sphaerica, which seems a typical phyllosphere inhabitant in tropical regions.

Even if the data correspond only to two sampling periods they show a high specialization of fungal forms and a succession of microfungi from young to senescent leaves of L. simplex.     

Localisations ultrastructurales dans le labyrinthe du placenta de chatte de la phosphatase acide de la thiamine pyrophosphatase et de la coloration par l'acide phosphotungstique à bas pH

Résumé Les localisations de la phosphatase acide (ACPase) et de la thiamine pyrophosphatase (TPPase) ont été recherchées dans le labyrinthe du placenta de chatte, durant les derniers jours de la gestation. L'ACPase est essentielement localisée au niveau du syncytiotrophoblaste, et dans la substance inerte interstitielle (S.I.I.) qui sépare les tissus foetaux des tissus maternels. La présence du produit de réaction, dans la lumière du système tubulaire lisse du syncytiotrophoblaste communicant avec la S.I.I., semble indiquer une origine syncytiotrophoblastique de l'activité ACPase de la S.I.I.L'activité TPPase se manifeste dans le syncytiotrophoblaste, rarement dans la Golgi mais toujours dans la lumière du système tubulaire. La présence de ces tubules TPPase positifs à la proximité de l'appareil de Golgi, semble indiquer une origine golgienne de ces structures qui pourraient véhiculer les phosphatases vers la S.I.I.Après action de l'acide phosphotungstique à bas pH, le cell coat de la face hémale de l'endothélium maternel est toujours bien visualisé, par contre la surface du syncytiotrophoblaste baignée par la S.I.I. n'est jamais marquée. Le dépôt intense de la lumière des tubules est en continuité avec celui de la S.I.I.L'activité ACPase de la S.I.I. doit permettre la dégradation de molécules maternelles durant leur transfert vers le sang foetal. La S.I.I. semble correspondre physiologiquement à la zone tampon immunitaire de l'interface des tissus maternels et foetaux.

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Ultrastructural localization of acid phosphatase and thiamine pyrophosphatase activities and of phosphotungstic staining at low pH in the placental labyrinth of the cat

Summary The localizations of acid phosphatase (ACPase) and thiamine pyrophosphatase (TPPase) activities were studied in the placental labyrinth of the cat during the last days of gestation. ACPase activities were observed essentially in the syncytiotrophoblast and in the interstitial inert substance (S.I.I.) that separates maternal from foetal tissues. Reaction product was localized in lysosomes, multivesicular bodies, and in the network of smoothmembraned tubules which open on the cell surface of the syncytiotrophoblast facing the S.I.I. The S.I.I. exhibit a strong activity, probably of syncytiotrophoblastic origin.TPPase activities were found in the syncytiotrophoblast, rarely in the Golgi apparatus but always in the lumen of the network of smooth-membrande tubules. The S.I.I. shows a moderate activity. These TPPase positive tubules being frequently observed very close to the Golgi cisternae, it is proposed that they arise from the Golgi complex and convey phosphatases to the S.I.I.After phosphotungstic acid staining at low pH, luminal surface coat of maternal endothelium is always strongly and continuously visualized, while the plasma membrane of the syncytiotrophoblast facing the S.I.I. is never stained. Staining is intense in the lumen of tubules, and continuous with the stain of the S.I.I.ACPase activity of the S.I.I. could be implicated in enzymatic degradation of maternal molecules during their transfer from maternal to foetal blood. The S.I.I. may correspond to the immunological buffer zone at the interface between maternal and foetal tissues.

     

Variation de la flore levuriforme de la cavité buccale entre sujets témoins et sujets soumis aux psychotropes

The yeasts of buccal cavity were studied in a group of seventy-five subjects treated by psychotropic drugs in a psychiatric hospital, in a group of fifty-one subjects treated by psychotropic drugs at home, and in a basis group (100+50). It is found yeasts on 84% of treated subjects in a psychiatric hospital and only 40% in the other populations.     

Observations ultrastructurales sur la parathyroïde de souris

Résumé La parathyroïde de souris ne diffère pas essentiellement par sa structure générale de celles des autres espéces étudiées. Les cellules glandulaires se caractérisent cependant par une plus grande richesse en matériel sécrétoire figuré. La présence de ce matériel figuré dans les cavités golgiennes permet de suivre l'élaboration de granules sécrétoires typiques d'un diamètre de 160 à 200 m qui sont spécialement abondants chez la souris. Ces granules ne sont pas excrétés au pôle vasculaire des cellules; ils migrent vers les parois cellulaires apicales et latérales, fusionnent avec la membrane plasmique et semblent être excrétés sous forme soluble dans les espaces intercellulaires. Il n'existe dans la parathyroïde de souris, comme dans celle du hamster et du rat, qu'un seul type cellulaire fondamental. Les éléments clairs et sombres ne diffèrent que par leur densité hyaloplasmique; cette différence s'accuse plus ou moins selon la qualité du prélèvement.

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Summary The structure of the mouse parathyroid does not differ essentially from other species studied. However, the glandular cells are characterized through an abundance in visible secretory material. The presence of this material in the cavities of the Golgi apparatus makes it possible to observe the formation of the typical secretory granules (160–200 m in diameter) which are particularly abundant in the mouse parathyroid. These granules are not secreted directly at the vascular pole; they migrate to the apical and lateral walls, fuse with the plasma membrane, and seen to pass into the cellular space in a soluble form. In the mouse parathyroid, as in the hamster and rat, there is only one fundamental cell type. The difference between dark and clear cells lies in the density of their hyaloplasm, which, however, is a consequence of the pretreatment of the material (fixation).

     

Quelques considérations sur l'enseignement de la médecine physique et de la réhabilitation

Particularly since World War II physical medicine and rehabilitation have assumed a growing importance. The efforts of the Canadian Association of Physical Medicine and Rehabilitation, following a survey of Canadian universities, to increase the theoretical and practical teaching of physiatrics are emphasized. It is considered important that the teaching of physical medicine and rehabilitation should be carried out concurrently with other medical and surgical teaching programs. Paramedical and auxiliary rehabilitation personnel should participate in the teaching program. The number of hours devoted to physiatrics should be increased, and the medical student should be permitted to choose physical medicine and rehabilitation as a part of his internship program.     

La spécificité d'action du mésoinositol,facteur de croissance pourEremothecium Ashbyii

Sans résumé     

Influence des paramètres de fumage sur l'activité génotoxique de la phase gazeuse de fumée de cigarette,mesurée sur le lymphocyte humain et la levure

Effect of smoking-machine parameters on the genetoxic activity of cigarette gas phase, estimated on human lymphocyte and yeastCigarette smoke used in chemical research and bioassays is obtained by mechanical smoking on machines adjusted to international standards. On studying the behavior of some smokers of black tobacco, we were led to change the standard parameters: volume, duration, frequency. The gas phase obtained under those new conditions is poorer in some components. This decrease goes with a clear-cut decrease of its genotoxic activity towards cultured human lymphocytes (sister-chromatid exchange frequency) and S. cerevisiae (rate of mitotic recombinants and of respiratory deficients). This investigation emphasizes the leading part of the smoking behavior.     

La Spécificité Parasitaire et ses Incidences sur l'Etiologie et l'Epidémologie des Parasitoses Humaines d'Origine Zoonotique

by J. Euzeby, Fondation Mérieux, 1997. 250.00FFr (153 pages) ISBN 2 84039 053 1.