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V. Labeyrie 《BioControl》1961,6(4):249-256
Summary No discovery of any parasite ofSphaeroderma rubidium
Graell.,Ceratapion carduorum
Kirbi, andDepressaria subpropinquella
Stain. has been mentioned for France.
However considerable collections ofMymaridae obtained on layings ofS. rubidium, show that parasitism may have a part in the limitation of this species.
The few parasites of larvae and pupae ofC. carduorum obtained do not seem to have any considerable regulating influence.
Although the parasitism of caterpillars ofD. subpropinquella byAngitia is frequent, the latter do not seem to be the essential factor in the evolution of the population of this species.
The caterpillars ofChoreutis bjerkandrella
thnb. may be used as a refuge by manyHymenoptera in summer, as a consequence of the scarcety ofMicrolepidoptera at a vulnerable stage.
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Carcinomas of unknown primary site (CUP) and paraneoplastic syndromes have the common characteristic that an extensive conventional biological and imaging analysis fails in some instance to detect the primary tumour. FDG-PET becomes recognized to provide interesting information in the case of “head and neck” CUP as well as in the case of neurological paraneoplastic syndromes biologically well defined. When, either CUP or paraneoplastic syndromes, are less defined, FDG-PET will not provide as much information as in the previous situation, although it can help in the etiologic diagnosis (oncologic or not) in some cases. 相似文献
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Today, the role of neuroimaging in the diagnosis of Alzheimer’s disease (AD) extends beyond its traditional role of excluding other conditions such as neurosurgical lesions. Modern challenges for neuroimaging techniques aim to contribute to the early diagnosis of AD. Early diagnosis includes recognition of pre-demented conditions, such as people with mild cognitive impairment (MCI) or with high risk of developing AD. In addition, early diagnosis would allow early treatment using currently available therapies or new therapies in the future. In this article, we will present the modern role of neuroimaging in AD. Structural MRI can detect and follow the time course of medial temporal lobe atrophy as a surrogate marker for the pathological process. New MRI techniques and image analysis software can detect subtle brain diffusion, perfusion or metabolic changes thus providing new tools for studying the pathological process. New ligands are also available for studies using tracers and positron emission tomography. 相似文献
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Sophie Rousseaux Cécile Caron Christophe Pivot-Pajot Anne Karen Faure Mira Hazzouri Bernard Sele Saadi Khochbin 《Andrologie》2003,13(2):139-147
Round spermatids are post-meiotic cells with a haploid genome contained in a nucleus, with a structure initially similar to that of the somatic cell nucleus. During spermatogenesis, the spermatid nucleus undergoes drastic remodelling during which it first elongates and then condenses into the very specific and tightly packaged structure of the sperm nucleus. During this remodelling dthe histones are replaced by transition proteins, which, in turn, are replaced by protamines, the specific nuclear proteins of the spermatozoa. Immediately prior to their replacement, the histones are hyperacetylated. The first part of our work was to precisely characterise the changes in histone acetylation during murine spermatogenesis. We have shown that the core histones H2A, H2B, H3 and H4 are hyperacetylated in the elongating spermatids. We have also shown that these changes in acetylation are associated with degradation of the enzymes responsible for histone deacetylation, histone deacetylases or HDACs, while histone acetyl transferases are still present in these cells. The histone acetylation pattern was also investigated during human spermatogenesis, revealing that histone hyperacetylation in the nucleus of elongating spermatids, which appears to be conserved during the course of evolution, also occurs during human spermatogenesis. Moreover, our data obtained from the testes of men with severely altered spermatogenesis, including SCO syndromes (Sertoli Cells Only Syndromes), show that a global hyperacetylation of the Sertoli cell nuclei is associated with an absence of meiotic and post-meiotic cells. This suggests that the global histone acetylation variations observed during spermatogenesis are part of a signalling pathway involving germ cell — Sertoli cell communication. Altogether, these data provide a basis for a better understanding of the mechanisms and identification of the factors involved in post-meiotic remodelling of chromatin. 相似文献
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Variations saisonnières de la production primaire dans les eaux de surface de la rivière du Saguenay
Raynald Côté 《Hydrobiologia》1981,83(1):3-10
Experiments of primary production were carried out at weekly intervals in the surface waters at one station (maximum depth of 20 m) in the Saguenay River, near Chicoutimi, during May–December 1978. The photic zone was very thin (maximum depth of 2 m). Phosphates are very low during the season sampling (maximum of 0.1 µat-g.–1). Maximum of production rates and biomass are respectively 3.5 mg C.m–3.h–1 and 3.7 mg.m–3. The river receives both industrial and urban runoff. Trace metals (Mercury, Copper, Lead, and Iron) seemed to be one of the important limiting factors for phytoplankton growth. 相似文献
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Sébastien Cimarelli Alessio Imperiale Frédérique Sauer Olivier Morel Dorra Ben Sellem Christian Goetz Cyrille Blondet Patrick Ohlmann André Constantinesco 《Médecine Nucléaire》2008,32(2):57-65
Transient left ventricular apical ballooning syndrome, also known as Takotsubo cardiomyopathy (TTC) was described for the first time in Japan in the earliest nineties. It represents 1 to 2 % of acute cardiac events and mimics closely acute myocardial infarction. The aim of this study was to investigate 99mTc-tetrofosmine or 201Thallium myocardial Single Photon Emission Computed Tomography (SPECT), 123I-metaIodoBenzylGuanidine (123I-mIBG) myocardial SPECT and myocardial Positron Emission Tomography using 18F-fluorodeoxyglucose (18F-FDG) in patients with TTC, assessing respectively left ventricular perfusion, innervation and metabolism. We studied four patients (three females) with TTC. We performed two weeks after acute phase (subacute phase) myocardial perfusion SPECT and 123I-mIBG myocardial SPECT for each patient. Two of them underwent myocardial PET with FDG. Then, we assessed left ventricular innervation and metabolism three months (chronic phase I) and more than six months (chronic phase II) after the acute phase. We compared the discrepancies between radionuclides uptake in the left ventricular apical region during a follow-up period of more than six months. In subacute phase, perfusion SPECT was normal for each patient. Conversely, 123I-mIBG SPECT and FDG-PET showed concordant apical uptake defect. This perfusion-metabolism pattern called “inverse flow-metabolism mismatch” is the metabolic state of stunned myocardium. After three months, we found improvement of apical tracer uptake in both FDG-PET and 123I-mIBG SPECT. These findings suggest that TTC is characterized by myocardial apical stunning which is related to a disturbance of cardiac sympathetic innervation. 123I-mIBG SPECT might be useful to diagnose earlier this pathology and to rule out acute myocardial infarction. 相似文献
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Résumé Candida albicans a été cultivé à l'obsurité, à 28 °C, dans un milieu de culture synthétique liquide dans lequel on fait varier les concentrations de glucose et d'azote. Des indices de chlamydosporulation ont pu etre calculés pour les milieux contenant au plus 0,08 g/l de glucose. Lorsque la concentration de glucose est plus importante, les thalles pseudomycéliens portent, dans certains cas, de nombreuses chlamydospores, mais aussi des chaines de cellules à contenu dense; ces thalles bourgeonnent des éléments levuriformes qui se détachent et continuent à bourgeonner dans le milieu de culture. Les différentes morphologies rencontrées sont décrites, illustrées et ordonnées en fonction des concentrations de glucose et d'azote du milieu.
Candida albicans was grown in the darkness, at 28 °C, in a synthetic medium in which glucose and nitrogen concentrations were varied. Numeric appraisal of the chlamydospore index was possible only in the medium where glucose concentration was 0,08 g/l or less. When the glucose concentration raised, pseudomycelial thalli bore numerous chlamydospores but sometimes also chains of cells with a dense granular content. These thalli bud yeast cells which separate and bud again in the medium. The different morphological aspects of the cultures are decribed, illustrated and classified according to the glucose and nitrogen concentration of the medium.相似文献
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《Médecine Nucléaire》2007,31(9):473-477
Recent advances in multislice computed tomography (MSCT), which might represent a minimally invasive alternative to coronary angiography (CA), have allowed the ability to analyze coronary arteries. In this review, we present the current diagnostic performance of MSCT, as compared with the reference standard (CA), for the assessment of native coronary arteries, coronary in-stent restenosis and coronary artery bypass graft. 相似文献
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André Malassiné 《Histochemistry and cell biology》1976,47(3):191-205
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.
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.相似文献
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Conclusions Par l'emploi de substrats radioactifs, il a été possible de montrer que le glucose, le ray-grass tel quel, la fraction soluble, les hemicelluloses et la fraction cellulosique du ray-grass ne sont pas, dans les conditions expérimentales appliquées, entièrement transformés en CO2 dans le sol après une période de deux mois.La décomposition du glucose est plus rapide que celle des hemicelluloses et celle-ci est plus rapide que celle de la fraction cellulosique. Pour le glucose et pour la fraction cellulosique, 11% et 15% respectivement ne se retrouvent pas sous forme de C14O2 tandis que pour la fraction soluble, pour les hemicelluloses et pour le ray-grass tel quel, c'est près de 20% qui ne sont pas oxydés en CO2.La décomposition de chacun de ces substrats radioactifs donne encore lieu à la production de produits organiques radioactifs que l'on trouve dans la fraction des substances solubles, dans la fraction groupant l'- et le -humus et dans l'humine. La radioactivité de cette dernière fraction est du même ordre de grandeur que la somme des deux autres fractions.Travail effectué sous les auspices de l'Institut pour l'Encouragement de la Recherche Scientifique dans l'Industrie et l'Agriculture (I.R.S.I.A.). 相似文献
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G. Bouxin 《Plant Ecology》1977,33(2-3):65-78
Résumé Dans un site de la forêt de montagne du Rwanda, diverses méthodes d'étude de la structure de la strate arborescente sont présentées. Grâce à diverses méthodes d'ordination et de classification, il est possible de représenter la distribution de la surface terrière de plusieurs espèces d'arbre le long d'un gradient d'humidité. L'analyse des coefficients de corrélation entre individus adultes et jeunes fait apparaître des différences entre l'écologie des arbres jeunes et adultes; à cause de la variance élevée des données, une standardisation est nécessaire. Le diamètre de l'arbre de surface terrière moyenne est une valeur de synthèse très intéressante sur le plan écologique. Les caractéristiques dendrométriques et écologiques de 4 groupements végétaux sont présentées; les courbes de fréquences de circonférences de trones sont un complément intéressant dans la compréhension de l'écologie des espèces.
Summary In a site of the Rwanda upland forest, different methods of study of the tree layer structure are presented. By using diverse ordination and classification methods, it is possible to represent the distribution of the basal area of several species along a moisture gradient. The analysis of the correlation coefficients between adult and young individuals of a same species exhibits differences in the ecology of young and adult trees; because of the high data variance, a standardization is necessary. The diameter of the tree of mean basal area is a very interesting synthesis value from an ecological point of view. The ecological and dendrometric characteristics of four groupings are presented; the frequency curves of trunk girth are an interesting complement to the understanding of the species ecology.
Toutes les données présentées ont été rassemblées pendant notre séjour à l'Institut national de la Recherche scientifique du Rwanda. Les ajustements à la fonction béta ont été réalisés sur l'ordinateur IBM 1130 de la Faculté des Sciences agronomiques de l'Etat à Gembloux; nous remercions vivement le Dr. J. Rondeux pour sa collaboration dans la réalisation du programme et des calculs. 相似文献
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F. E. Floc'h J. Biguet S. Andrieu A. Vernes collaboration technique de Madame R. Popeye & Monsieur J. LeClercq 《Mycopathologia》1974,54(4):475-483
Mice were inoculated with different quantities of blastospores ofCandida albicans by subcutaneous or intravenous ways. Delayed hypersensitivity was then studied during the course of infection by means of the inhibition of macrophage spreading test. In the same time retrocultures were done from kidney material, target organs in the experimental candidiasis. The results obtained in this way enabled the authors to think that cellular immunity plays a role in this experimental model as described by Mackaness.
Travail de l'Unité 42 de l'INSERM et du Groupe de Mycologie Fondamentale et Appliquée de LILLE. 相似文献
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