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121.
To study the role of different structures of a plant surface preventing insect attachment, a variety of plant surfaces were screened. Attachment ability of the beetle Chrysolina fastuosa Scop. (Coleoptera, Chrysomelidae) was measured on 99 surfaces among them smooth, hairy, felt-like, waxy, and glandular ones of three plant organs (stems, leaves, fruits) of 83 plant species belonging to 45 families. Insects attached successfully to smooth, hairy, and felt-like substrata. These surface types did not effect the further attachment of C. fastuosa, indicating the adhesive system remained intact after contacting these substrata. However, the beetles could not attach properly to surfaces covered with wax crystalloids or glandular hairs. In most experiments on pruinose plant substrata, no influence of the surfaces on the subsequent attachment ability of insects was observed. Only in one case (the stem of Acer negundo), was such an impairment recorded, but recovery of attachment ability was fast. Crystalloids of this plant species probably temporarily disable function of tenent setae of C. fastuosa. Four hypotheses, explaining anti-adhesive properties of plant surfaces, covered with wax crystalloids are proposed. A plant surface with glandular trichomes disabled the attachment system of the beetle for a long time. Secretions of trichomes probably glue tenent setae together making further attachment impossible.  相似文献   
122.
Eighty-three cases having a cervical smear result showing abnormal glandular cells were identified and matched up with the diagnostic histology result. Thirty-four (41.0%) were associated with malignancy and 26 (31.3%) with a cervical intraepithelial lesion without invasion. Thirty-eight (45.8%) had conditions of the cervix as follows: 12 cases had invasive disease of the cervix; nine (10.8%) adenocarcinoma of cervix and three (3.6%) squamous carcinoma of cervix. Nineteen (22.9%) had cervical intraepithelial neoplasia (CIN/SIL) alone and seven (8.4%) had cervical glandular intraepithelial neoplasia (CGIN) +/- CIN. There were 16 (19.3%) cases with malignancies of the uterine corpus and six (7.2%) had a malignancy arising from another primary site. Twenty-three (27.7%) had no malignant or pre-malignant condition. The risk of malignancy was related to age and ranged from 18.2% in those under 35 years to 67.9% in those 55 years and over. A protocol for the management of these cases is described.  相似文献   
123.
124.
Domino SE  Hurd EA 《Glycobiology》2004,14(2):169-175
The secretor gene (FUT2) encodes an alpha(1,2)fucosyltransferase (E.C. 2.4.1.69) that elaborates alpha(1,2)fucose residues on mucosal epithelium and secreted mucins. Though uterine alpha(1,2)fucosylated glycans have been proposed to be involved in embryo adhesion, mice with a homozygous null mutation of Fut2 displayed normal fertility. To help develop alternative hypotheses for function, the cell type and regulation of Fut2 expression during the estrous cycle, hormone replacement, and pregnancy was examined in Fut2-LacZ reporter mice containing targeted replacement of Fut2 with bacterial lacZ. LacZ expression in the reproductive tract of Fut2-LacZ mice is most prominent in the glandular epithelium of the endocervix during estrus and pregnancy. Nuclear LacZ expression identifies cell-specific expression of Fut2 in mucus-secreting cells of the endocervix, uterine glands, foveolar pit and chief cells of the stomach, and goblet cells of the colon. In ovariectomized Fut2-LacZ mice, estradiol treatment stimulates X-gal staining in endocervix and uterus but does not affect expression in stomach and colon. Northern blot analysis in wild-type mice shows 15-fold elevations of Fut2 steady-state mRNA with estradiol treatment, whereas Fut1 varies little. Fut2 levels in the glandular stomach and distal colon remain constant, and uterine Fut2 levels vary eightfold during the estrous cycle. These data represent the first demonstration of a glycosyltransferase gene under tissue-specific hormonal regulation in a LacZ reporter mouse model. Endocervical expression of Fut2 in estrus and pregnancy may modify cervical mucus barrier properties from microbial infection analogous to the potential role of mucosal glycans in humans.  相似文献   
125.
Hypochlora alba (Dodge) is a specialist grasshopper that lives and feeds almost exclusively on the sage brush Artemisia ludoviciana Nutt., a plant mostly avoided by the generalist grasshopper Melanoplus sanguinipes (Fabr.). Analysis of leaves, seed heads, and glandular trichomes by gas chromatography-mass spectrometry revealed 1,8-cineole, camphor and borneol to be the major monoterpenes and achillin the major sesquiterpene lactone. These terpenoids increased over the growing season and were two to five times more concentrated in the seed heads than in the leaves. Gustatory choice tests showed a feeding stimulant(s) for H. alba to be present in extracts of A. ludoviciana and A. carruthii Wood, a closely related species that H. alba will feed upon, but not in a non-host species, A. filifolia Torr. This stimulant activity was found in a fraction containing primarily monoterpene hydrocarbons. Other fractions containing sesquiterpene lactones had antifeedant activity against M. sanguinipes. Tests with achillin showed the average foliar levels (ca. 2% dry weight) to be above the rejection threshold of the generalist (0.5%) but below that of the specialist (4%). Reproductive tissue contained average levels greater (ca. 7%) than the rejection threshold of either species.
Résumé Hypochlora alba Dodge, orthoptère spécialiste, consomme presque exclusivement A. ludoviciana, plante produisant des terpènes en grandes quantités dans ses trichomes glandulaires. Cette plante n'est pas consommée par des orthoptères généralistes, comme Melanoplus sanguinpes Fabr. L'analyse d'extraits et de fractions de la plante en chromatographie en phase gazeuse associée à la spectrométrie de masse a révélé de nombreux monoterpènes (1,8-cinéole, camphre, bornéol et autres) et une grande quantité d'achilline, lactone sesquiterpène. Ces terpènes étaient 2 à 5 fois plus concentrés dans les organes reproducteurs de l'armoise que dans ses organes végétatifs. La concentration de terpènes dans les feuilles augmente de la plante jeune jusqu'à la maturité. Les plantes ont présenté une grande variabilité en concentrations relative et totale en terpènes. L'influence des terpènes dans la régulation du comportement alimentaire du spécialiste et du généraliste a été examinée par des tests de choix gustatif sur des disques de membrane. Des extraits de A. ludaviciana et de A. carruthii Wood,-espèce très voisine que H. alba peut consommer-, contenaient un (ou plusiers) phagostimulants de H. alba, tandis que A. filifolia Torr., espèce non consommée, n'en contenait pas. Cette activité stimulatrice était éluée dans la moins polaire des 5 fractions, qui contenait principalement les hydrocarbones monoterpènes. La prise de nourriture de M. sanguinipes a été stimulée par des extraits des 3 armoises examinées, et par les 3 premières fractions de A. ludoviciana, tandis que ses 2 dernières fractions, contenant les lactones sesquiterpènes, ont présenté une action phagodissuasive. Des tests avec l'achilline, principale lactone sesquiterpène, ont montré que sa concentration moyenne dans les feuilles (2% du poids frais) était supérieure au seuil de rejet du généraliste (0,5%), mais inférieure à celui du spécialiste (4%). La concentration moyenne des organes reproducteurs (7%) était supérieure au seuil de rejet des deux espèces.
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126.
丁酸钠对人胃腺癌SGC-7901细胞的生物学效应   总被引:1,自引:0,他引:1  
应用兔抗纤维粘(连)蛋白(FN)抗体和兔抗3t,5,环腺苷酸(cAMP)特异性抗体,并用羊抗兔IgG荧光抗体,在荧光显微镜下观察丁酸钠对人胃腺癌SGC一7901细胞系的纤维粘(连)蛋白(FN)和cAMP水平的变化。实验结果表明丁酸钠有增强SGC一7901细胞内纤维粘(连)蛋白(FN)和c.~MP水平的作用;应用电镜细胞化学和扫描电镜的技术方法,观察到人胃腺癌SGC一7901细胞在丁酸钠作用下膜表而(Na 一K )一ATP酶活性明显下降;微绒毛明显减退,膜表面较光滑。这可能说明丁酸钠通过抑制(Na~一K )一ATP酶活性,提高了细咆内cAMP水平,调控细胞的增殖和分化。  相似文献   
127.
2-Undecanone, a compound found in the tips of the Type VI glandular trichomes of the wild tomato species Lycopersicon hirsutum f. glabratum C. H. Mull (accession PI 134417), when incorporated in artificial diet, was previously shown to cause pupal deformity and mortality among Heliothis zea (Boddie). In the present study, the developmental stage of H. zea sensitive to the effects of dietary 2-undecanone was determined by rearing larvae through the fourth instar on diet with or without 2-undecanone, then transferring them to new diet either with or without 2-undecanone. Dietary levels of 2-undecanone (0.055% wet wt) were representative of concentrations found in PI 134417 foliage. Ingestion of 2-undecanone during the fifth instar was both necessary and sufficient to cause pupal mortality. Rearing fifth instar H. zea on PI 134417 foliage with glandular trichomes intact (2-undecanone present at 0.084±0.026% wt wt) or with the trichomes, and hence 2-undecanone, removed indicated that these effects occur in planta. Potential implications of these findings for using 2-undecanone-mediated resistance for insect pest management are discussed.
Résumé Il a été démontré précédemment que l'undécanone-2, présente dans les extrémités des trichomes glandulaires de type VI de la tomate sauvage Lycopersicon hirsutum glabratum C. H. Mull (accession PI 134417), provoque déformations et mortalité chez les chrysalides de Heliothis zea (Boddie) lorsqu'elle est incorporée dans une nourriture artificielle. Dans cette étude, le stade de développement de H. zea sensible aux effets de l'undécanone-2 a été déterminé en élevant les larves jusqu'au 4e stade sur une diète contenant ou non de l'undécanone-2, puis en les transférant sur une nouvelle diète avec ou sans undécanone-2. Les concentrations en undécanone-2 utilisées (0.055% du poids frais) étaient comparables aux concentrations présentes dans les feuilles du PI 134417. L'ingestion de l'undécanone-2 durant le 5e stade s'est avérée nécessaire et suffisante pour provoquer une mortalité au stade chrysalide. L'élevage du 5e stade de H. zea sur des feuilles de PI 134417 dont les trichomes sont intacts (l'undécanone-2 est présente à la concentration de 0.084±0.025% du poids frais) ou sur des feuilles dont les trichomes, et par conséquent l'undécanone-2, ont été éliminés, a démontré que les effets toxiques se produisent in planta.L'undécanone-2 pourrait être un facteur de résistance efficace des tomates, mais probablement uniquement dans les régions où H. zea est polyvoltime sur la tomate et où les premiéres générations se développent sur le feuillage pendant toute la période larvaire avant la maturation des fruits. Normalement, les premiers stades larvaires de H. zea se nourrissent de feuilles et les derniers stades des fruits. Les fruits ne contenant pas d'undécanone-2, les chenilles qui se développeraient sur les plants en fructification pourraient échapper aux effets toxiques.
  相似文献   
128.
As a first line of defense against insect herbivores many plants store high concentrations of toxic and deterrent secondary metabolites in glandular trichomes. Plant Pleiotropic Drug Resistance (PDR)‐type ABC transporters are known secondary metabolite transporters, and several have been implicated in pathogen or herbivore defense. Here, we report on Petunia hybrida PhPDR2 as a major contributor to trichome‐related chemical defense. PhPDR2 was found to localize to the plasma membrane and be predominantly expressed in multicellular glandular trichomes of leaves and stems. Down‐regulation of PhPDR2 via RNA interference (pdr2) resulted in a markedly higher susceptibility of the transgenic plants to the generalist foliage feeder Spodoptera littoralis. Untargeted screening of pdr2 trichome metabolite contents showed a significant decrease in petuniasterone and petuniolide content, compounds, which had previously been shown to act as potent toxins against various insects. Our findings suggest that PhPDR2 plays a leading role in controlling petuniasterone levels in leaves and trichomes of petunia, thus contributing to herbivory resistance.  相似文献   
129.
The aim of this work was to research and evaluate the performance of three different digital breast tomosynthesis (DBT) systems in the clinical environment (Siemens Mammomat Inspiration, Hologic Selenia Dimensions, and Fujifilm Amulet Innovality). The characterization included the study of the detector, the automatic exposure control, and the resolution of DBT projections and reconstructed planes.The modulation transfer function (MTF) of the DBT projections was measured with a 1 mm thick steel edge, showing a strong anisotropy (30–40% lower MTF0.5 frequencies in the tube travel direction). The in-plane MTF0.5, measured with a 25 μm tungsten wire, ranges from 1.3 to 1.8 lp/mm in the tube-travel direction and between 2.4 and 3.7 lp/mm in the chest wall–nipple. In the latter direction, the MTF peak shift is more emphasized for large angular range systems (2.0 versus 1.0 lp/mm). In-depth resolution of the planes, via the full width at half maximum (FWHM) from the point spread function of a 25 μm tungsten wire, is not only influenced by angular range and yields 1.3–4.6 mm among systems. The artifact spread function from 1 mm diameter tungsten beads depends mainly on angular range, yielding two tendencies whether large (FWHM is 4.5 mm) or small (FWHM is 10 mm) angular range is used. DBT delivers per scan a mean glandular dose between 1.4 and 2.7 mGy for a 45 mm thick polymethyl methacrylate (PMMA) block.In conclusion, we have identified and analysed specific metrics that can be used for quality assurance of DBT systems.  相似文献   
130.
The resistance of accession PI 134417 of the wild tomato Lycopersicon hirsutum f. glabratum C. H. Mull to Manduca sexta (L.) (Lepidoptera: Spingidae) and Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) is conditioned by the high densities of 2-tridecanone-containing, glandular trichomes associated with the foliage. In laboratory experiments, rates of parasitism of M. sexta eggs by Telenomus sphingis (Ashmead) (Hymenoptera: Scelionidae) were lower among eggs on PI 134417 foliage than among eggs on foliage of the cultivated tomato L. esculentum Mill. (cv. Better Boy). The latter is characterized by a significantly lower density of type VI glandular trichomes than PI 134417 and an absence of 2-tridecanone. Parasitism by T. sphingis was also reduced among eggs on foliage of the F1 hybrid between PI 134417 and L. esculentum. The hybrid foliage lacks 2-tridecanone but has a density of type VI glandular trichomes that is intermediate between those of PI 134417 and L. esculentum, indicating that elevated densities of type VI glandular trichomes adversely affect T. sphingis. This conclusion was further substantiated by the finding that there were no differences among plant lines in the levels of parasitism of M. sexta eggs when the eggs were on foliage that had been divested of glandular trichomes.In bioassays in which T. sphingis adults or immatures in host eggs were exposed to filter paper treated with 2-tridecanone at rates comparable to those associated with PI 134417 foliage, 2-tridecanone was acutely toxic and caused high levels of mortality. In addition, at high concentrations, 2-tridecanone vapors were repellent to T. sphingis adults. However, when exposed to PI 134417 foliage, few T. sphingis adults were killed.Parasitism of M. sexta eggs was unaffected when the eggs were deposited by moths reared as fifth instar larvae on diet containing 2-tridecanone and/or 2-undecanone at levels comparable to those associated with PI 134417 foliage.  相似文献   
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