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Anaemia is common in patients older than 75 years. Patho-physiologic mechanisms of anaemia are similar to that involved in younger patients even though certain mechanisms are more common in the elderly. Practical decisional algorithms have to be used for the diagnosis of anaemia. Risk factors for anaemia have been identified in this age group: institutionalization, bad socio-economic conditions, co-morbid conditions. Particular emphasis is given to several points:
  1. The clinical tolerance of anaemia is the most important feature to take into account in older patients, rather than the decline of the haemoglobin level. Even if the haemoglobin level is only slightly decreased, evaluation of anaemia should be performed by the geriatrician, including, if needed, the achievement of a bone-marrow aspiration.
  2. Causes of anaemia are often multiple, due to frequent comorbid conditions and acute illnesses, associated with nutritional deficiencies, inflammation… Chronic kidney disease and dysthyroidia are also common.
  3. Nutritional deficiencies (iron, folate and/or B12 deficiency) are frequent and their cause has to be identified.
  4. The prevalence of myelodysplastic syndromes, which are clonal diseases, is probably underestimated in this age group.
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As the population ages, pneumonia has become a main public health problem because of its increasing incidence and its increasing severity with age. Pneumonia in the elderly is a special entity with specific pathogenesis and requires specific management. Ageing is associated with modifications in lung performance, modifications in oropharyngeal flora, and is frequently associated with additional risk factors and comorbidities. The diagnosis of pneumonia in the elderly is a clinical challenge because of a non-typical symptomatology, a poor diagnosis yield of microbiological analysis. In this context, the treatment relies on empirical antibiotic therapy, which takes into account the specificities of older patients.  相似文献   

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The collections of live plants at the National Museum of Natural History in Paris (Australian and Tropical Green Houses, Alpine Garden, Chevreloup's Arboretum and Menton's Exotic Garden) include many ornamental and also many medicinal and aromatic plants which are threatened or only represented by a few individuals.

Firstly, a palynological inventory of more than 250 species allowed an evaluation of the male gametophyte (pollen) biodiversity of these collections. The study is illustrated by observations using scanning electron microscopy. These are sixteen of Dicotyledons and eight Monocotyledons selected according to the systematic and conservation status of the plant and the originality or representativity of their pollen type and structure: Dicotyledons: Peumus, Harrisia, Fenestraria, Sparmannia, Bauhinia, Banksia, Sarcocaulon, Reinwardtia, Mina, Jaborosa, Whitfieldia, Thunbergia, Martynia, Sesamothamnus. Felicia. Monocotyledons: Cyperus, Billbergia, Spathiphyllum, Furcraea, Crinum, Iris, Aloe, Lapageria.

Original and remarkable structures were observed which deserve more detailed studies in Peumus boldus, Sarcocaulon vanderietiæ; and Reinwardtia trigyna, in the Dicotyledons, and in Spathiphyllum floribundum and Furcraea selloa in the Monocotyledons.

Secondly a pollen bank was created in 1983 at the Palynologivcal Laboratory, using a particular technic of freeze-drying developed there. Some ‘models’, sorted out from the above mentioned collections, have been included in the bank in order to contribute:

— to the management of the genetic patrimony of these living collections

— to their conservations as wild plants.

Eight Dicotyledons and four Monocotyledons were tested with respect to preservation and storage schedule at various temperatures: Dicotyledons: Helxine, Sparmannia, Raphiolepis, Aeonium, Callistemon, Jasminum, Petunia, Viburnum. Monocotyledons: Clivia, Lapageria, Crinum, Iris. These latter studies stress that, once the germination medium is well defined, pollen preserved by freezedrying and stored at — 80°C seem the best protected for long survival.

Les collections végétales vivantes du Muséum National d'Histoire Naturelle (Serres australienne et tropicale, Jardin alpin, Serres de Chèvreloup, Jardin exotique de Menton) renferment beaucoup de plantes ornementales, mais aussi de nombreuses plantes médicinales et aromatiques, parfois menaceés ou représentées à trés peu d'exemplaires.

D'une part, un inventaire palynologique, portant sur plus de 250 espèces a permis une évaluation de la Biodiversité du gamétophyte mâle (pollen), à travers ces collections. Ce travail est illustré par des observations faites en Microscopie Electronique à Balayage. Elles portent sur un choix de 16 Dicotylédones et 8 Monocotylédones, choix établi en fonction de la plante (position systématique, plante menacée), et de l'originalité ou de la représentativité du type de pollen et de sa structure: Dicotylédones: Peumus, Harrisia, Fenestraria, Sparmannia, Drosera, Bauhinia, Banksia, Sarcocaulon, Reinwardtia, Mina, Jaborosa, Whitfieldia, Thunbergia, Martynia, Sesamothamnus, Felicia. Monocotylédones: Cyperus, Billbergia, Spathiphyllum, Furcraea, Crinum, Iris, Aloë, Lapageria.

Des structures originales, remarquables, celles par exemple de Peumus boldus, Sarcocaulon vanderietia, Reinwardtia frigyna, pour les Dicotylédones, Spathiphyllum floribundum, Furcraea selloa pour les Monocotylédones, ont été observées et mériteraient des études plus appronfondies.

D'autre part, une Banque de pollens ayant été crée, en 1983, au Laboratoire de Palynologie, à partir d'une technique particuliére de lyophilisation mise au point par nos soins, certains “modèles”, issues de ces collections, ont été introduits dans la Banque afin d'apporter une contribution:

— à la gestion du Patrimoine génétique de ces collections végétales vivantes

— et à leur conservation, en tant qu'espèces sauvages.

Huit Dicotylédones et quatre Monocotylédones ont été testées tout au long de leur conservation et de leur stockage à des températures différentes: Dicotylédones: Helxine, Sparmannia, Raphiolepis, Aeonium, Callistemon, Jasminum, Petunia, Viburnum. Monocotylédones: Clivia, Lapageria, Crinum, Iris.

Il ressort de ces dernières études que, une fois le milieu de germination bien défini, les pollens, conservés par lyophilisation et stocées à 80°C, semblent être les mieux protégés pour atteindre une survie de longue durée.  相似文献   

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Lebrun  J. 《Plant Ecology》1954,5(1):157-160
Sans résuméReçu par la rédaction le 28.I.1954.  相似文献   

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Résumé Plusieurs méthodes cytochimiques utilisées convergent pour indiquer l'existence d'une réactivité du plasmalemme, qui le distingue des autres cytomembranes. 1. Des résultats positifs constants ont été obtenus avec deux sortes de méthodes. Certaines sont effectues sur pièces, utilisant la capture de métaux colloïdaux par les groupements électronégatifs. D'autres sont réalisées sur coupes ultrafines: technique dérivant de l'APS et méthode utilisant l'acide phosphotungstique à bas pH, dans différents milieux d'inclusion. 2. D'autres méthodes fournissent des résultats plus sporadiques, en particulier les techniques de détection d'ions inorganiques.Ces données cytochimiques tendent à indiquer l'existence d'une sorte de glycocalyx au niveau du plasmalemme végétal, évoquant celui des cellules animales. Il s'en distingue toutefois par certains caractères (absence d'action de la neuraminidase). La confrontation de ces résultats avec ceux obtenus après les tests d'activité enzymatique ou après des études histoautoradiographiques, confirme l'idée d'une organisation du plasmalemme, liée à son activité.Ces résultats fournissent des précisions sur les modalités de différenciation des membranes et sur leurs relations dans les phénomènes d'échange entre la cellule et le milieu extérieur (pinocytose, émission de vésicules sécrétrices).
Reactivity of the plasmalemma. Cytochemical study
Summary Several cytochemical methods converge to indicate a reactivity of the plasmalemma, which makes it different from others cytomembranes. 1. Positive and constant results are obtained with two kinds of methods. Some are performed on specimen blocks, using the binding of colloidal metals with electronegative groups; some are performed on ultrathin sections: procedure derivating from PAS reaction, and method using phosphotungstic acid at a low pH in different embedding resins (epon, araldite, methacrylate, glycol-methacrylate). 2. Rather sporadic results are obtained with other procedures, specially those which demonstrate inorganic ions.These cytochemical data tend to indicate the existence, at the level of the plasmalemma, of a kind of glycocalyx similar to that described in animal cells. It is however different in some characteristics (neuraminidase has no effect on its reactivity).After a comparison of the results with those obtained from enzymatic tests or autoradiographic studies, the idea of a special activity of the plasmalemma is enhanced.These results give some informations on the ways the differenciation of cytomembranes occurs, and on their relations during exchanges between the cell and the exterior (pinocytosis and emission of secretory vesicles).

Abréviations f fossette sécrétrice (anfractuosité du plasmalemme contenant des polysaccharides) - G dictyosome (appareil de Golgi) - ls lomasome - m mitochondrie - mn membrane nucléaire - mt méat - n noyau - P paroi - pe plasmalemme (pellicule ectoplasmique) - pl plaste - ps plasmodesme - re reticulum endoplasmique - sl slime body (corps muqueux de tube criblé) - t tractus polysaccharidique reliant cytoplasme et paroi - v vésicule cytoplasmique - va vacuole - Grossissement sur chaque cliché, le trait représente 0,5 micron  相似文献   

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Seminal liquefaction corresponds to a proteolysis of glycoproteins and could also result in a lysis of linked glycans involving glycosidases. It is well known that α-1-4 glucosidase is a real epipidymal marker. The aim of this study is to point out new markers among the glycosidases and especially β-D-mannosidase, α-L-fucosidase and N-acetyl-β-D-glucosaminidase. There is no correlation between the three enzymatic activities and the sperm count. Moreover in case of azoospermia enzymatic activities were always present. The variations observed are both quantitative (β-MAN activity is significantly decreased) and qualitative (modifications of the relative proportions of the different enzymatic forms) according to the etiology of azoospermia.  相似文献   

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